diff --git a/.coderabbit.yaml b/.coderabbit.yaml
index e85513904..f50288895 100644
--- a/.coderabbit.yaml
+++ b/.coderabbit.yaml
@@ -25,7 +25,7 @@ reviews:
     - path: 'src/lib/server/**'
       instructions: |
         - This directory is server-only. Never import from client-side code or Svelte components.
-        - DB client must be accessed only via `$lib/server/database`.
+        - DB client must be accessed only via `#lib/server/database.js`.
     # --- Schema / validation ---
     - path: 'src/**/zod/**'
       instructions: |
diff --git a/docs/guides/agent-rules/testing-e2e.md b/docs/guides/agent-rules/testing-e2e.md
index 1c38e55ae..71e826e21 100644
--- a/docs/guides/agent-rules/testing-e2e.md
+++ b/docs/guides/agent-rules/testing-e2e.md
@@ -10,14 +10,14 @@ paths:
 ## Setup
 
 - File extension: **must** be `.spec.ts` (`.test.ts` not detected by `playwright.config.ts`)
-- No path aliases or subpath imports (`$features` is resolved only by Vite; `#lib/*.js` resolves to `src/lib/*.js`, but the Playwright runner does not map it to the `.ts` source). Use type-only imports for types:
+- No runtime imports through subpath imports (`#lib/*.js` and `#features/*.js` resolve to `src/**/*.js`, but the Playwright runner does not map them to the `.ts` source). Use relative imports, or type-only imports for types:
 
 ```typescript
 // Bad: runtime import fails in E2E
-import { TAB_SOLUTION } from '$features/workbooks/types/workbook';
+import { TAB_SOLUTION } from '#features/workbooks/types/workbook.js';
 
 // Good: type-only import + local constant
-import type { WorkBookTab } from '$features/workbooks/types/workbook';
+import type { WorkBookTab } from '#features/workbooks/types/workbook.js';
 
 const TAB_SOLUTION: WorkBookTab = 'solution';
 ```
diff --git a/docs/guides/architecture.md b/docs/guides/architecture.md
index 9f35fb9b5..4b7f08bcd 100644
--- a/docs/guides/architecture.md
+++ b/docs/guides/architecture.md
@@ -139,16 +139,16 @@ include: [
 ];
 ```
 
-### 6. path alias と subpath imports
+### 6. subpath imports（`#lib`・`#features`）
 
-`src/lib` は `package.json#imports` の `#lib/*` で参照する。SvelteKit 3 で組み込みの `$lib` が削除されるため `$lib` は使わず、oxlint と ESLint の `no-restricted-imports` で禁止している。
-`#lib` には明示的な拡張子が必要で、TS モジュールは `.js`、コンポーネントは `.svelte`、runes モジュール（`.svelte.ts`）は `.svelte.js` と書く。`vi.mock` の specifier も同じ形にする。
-lint が検出するのは import・export 宣言（`import type`・`export … from` を含む）と `.ts` の動的 `import()` で、`vi.mock('$lib/...')` と `.svelte` 内の動的 `import()` は検出しない。import の specifier をまとめて変えたときは、`rg -n '\$lib' src e2e prisma` で残りが無いことも確かめる。
-`$features` は `svelte.config.js` の alias で定義している。
+`src/lib` は `package.json#imports` の `#lib/*`、`src/features` は `#features/*` で参照する。SvelteKit 3 は組み込みの `$lib` を削除し、`kit.alias` も非推奨にするため、`svelte.config.js` に alias は置かない。
+拡張子は明示する。TS モジュールは `.js`、コンポーネントは `.svelte`、runes モジュール（`.svelte.ts`）は `.svelte.js` と書く。`vi.mock` の specifier も同じ形にする。
+`$lib` は Kit 2 が組み込みで解決してしまうため、oxlint と ESLint の `no-restricted-imports` で禁止している。lint が検出するのは import・export 宣言（`import type`・`export … from` を含む）と `.ts` の動的 `import()` で、`vi.mock('$lib/...')` と `.svelte` 内の動的 `import()` は検出しない。`$features` と `@/` は alias が無いので、import すると型チェックで失敗する。
+import の specifier をまとめて変えたときは、`rg -n '\$lib|\$features|@/' src e2e prisma` で残りが無いことも確かめる。
 
 ```typescript
 import { formatDate } from '#lib/utils/format.js';
-import WorkBookForm from '$features/workbooks/components/shared/WorkBookForm.svelte';
+import WorkBookForm from '#features/workbooks/components/shared/WorkBookForm.svelte';
 import type { PageServerLoad } from './$types';
 ```
 
diff --git a/package.json b/package.json
index d16d1b94c..4ee8d36dd 100644
--- a/package.json
+++ b/package.json
@@ -71,7 +71,8 @@
   },
   "type": "module",
   "imports": {
-    "#lib/*": "./src/lib/*"
+    "#lib/*": "./src/lib/*",
+    "#features/*": "./src/features/*"
   },
   "dependencies": {
     "@dnd-kit/helpers": "0.5.1",
diff --git a/src/app.d.ts b/src/app.d.ts
index ec0f9a009..30b104fb9 100644
--- a/src/app.d.ts
+++ b/src/app.d.ts
@@ -7,7 +7,7 @@ declare global {
   namespace App {
     // interface Error {}
     interface Locals {
-      auth: import('$features/auth/server/auth').AuthRequest;
+      auth: import('#features/auth/server/auth.js').AuthRequest;
       user: {
         id: string;
         name: string;
diff --git a/src/features/tasks/components/contest-table/TaskTable.svelte b/src/features/tasks/components/contest-table/TaskTable.svelte
index ab635fa87..302492f9b 100644
--- a/src/features/tasks/components/contest-table/TaskTable.svelte
+++ b/src/features/tasks/components/contest-table/TaskTable.svelte
@@ -18,18 +18,18 @@
     ContestTableProvider,
     ContestTableDisplayConfig,
     ContestTableMetaData,
-  } from '$features/tasks/types/contest-table/contest_table_provider';
+  } from '#features/tasks/types/contest-table/contest_table_provider.js';
   import type { ContestTaskPairKey } from '#lib/types/contest_task_pair.js';
-  import type { VoteStatisticsMap } from '$features/votes/types/vote_result';
+  import type { VoteStatisticsMap } from '#features/votes/types/vote_result.js';
 
   import TaskTableBodyCell from './TaskTableBodyCell.svelte';
 
-  import { activeContestTypeStore } from '$features/tasks/stores/active_contest_type.svelte';
+  import { activeContestTypeStore } from '#features/tasks/stores/active_contest_type.svelte.js';
   import {
     contestTableProviderGroups,
     type ContestTableProviderGroup,
     type ContestTableProviderGroups,
-  } from '$features/tasks/utils/contest-table/contest_table_provider';
+  } from '#features/tasks/utils/contest-table/contest_table_provider.js';
 
   import { useLocalStorage } from '#lib/stores/local_storage_helper.svelte.js';
 
diff --git a/src/features/tasks/components/contest-table/TaskTableBodyCell.svelte b/src/features/tasks/components/contest-table/TaskTableBodyCell.svelte
index 47197ed3d..af899be68 100644
--- a/src/features/tasks/components/contest-table/TaskTableBodyCell.svelte
+++ b/src/features/tasks/components/contest-table/TaskTableBodyCell.svelte
@@ -1,13 +1,13 @@
 <script lang="ts">
   import type { TaskResult } from '#lib/types/task.js';
-  import type { VoteStatisticsMap } from '$features/votes/types/vote_result';
+  import type { VoteStatisticsMap } from '#features/votes/types/vote_result.js';
 
-  import VotableGrade from '@/features/votes/components/VotableGrade.svelte';
+  import VotableGrade from '#features/votes/components/VotableGrade.svelte';
   import ExternalLinkWrapper from '#lib/components/ExternalLinkWrapper.svelte';
   import UpdatingDropdown from '#lib/components/SubmissionStatus/UpdatingDropdown.svelte';
 
   import { getTaskUrl, removeTaskIndexFromTitle } from '#lib/utils/task.js';
-  import { formatAojTitle } from '$features/tasks/utils/contest-table/aoj_labels';
+  import { formatAojTitle } from '#features/tasks/utils/contest-table/aoj_labels.js';
 
   interface Props {
     taskResult: TaskResult;
diff --git a/src/features/tasks/stores/active_contest_type.svelte.test.ts b/src/features/tasks/stores/active_contest_type.svelte.test.ts
index 90967b826..c6b1c998d 100644
--- a/src/features/tasks/stores/active_contest_type.svelte.test.ts
+++ b/src/features/tasks/stores/active_contest_type.svelte.test.ts
@@ -2,11 +2,11 @@
 
 import { describe, test, expect, vi, beforeEach, afterEach } from 'vitest';
 
-import type { ContestTableProviderGroups } from '$features/tasks/utils/contest-table/contest_table_provider';
+import type { ContestTableProviderGroups } from '#features/tasks/utils/contest-table/contest_table_provider.js';
 import {
   activeContestTypeStore,
   ActiveContestTypeStore,
-} from '$features/tasks/stores/active_contest_type.svelte';
+} from '#features/tasks/stores/active_contest_type.svelte.js';
 
 // WHY: a single dynamic mock is the only way to toggle `browser` per describe. Every vi.mock is
 // hoisted and the last registration for a module wins, so a second vi.mock of `$app/environment`
diff --git a/src/features/tasks/stores/active_contest_type.svelte.ts b/src/features/tasks/stores/active_contest_type.svelte.ts
index 95f1a75f6..d66ff91bb 100644
--- a/src/features/tasks/stores/active_contest_type.svelte.ts
+++ b/src/features/tasks/stores/active_contest_type.svelte.ts
@@ -2,7 +2,7 @@ import { useLocalStorage } from '#lib/stores/local_storage_helper.svelte.js';
 import {
   type ContestTableProviderGroups,
   contestTableProviderGroups,
-} from '$features/tasks/utils/contest-table/contest_table_provider';
+} from '#features/tasks/utils/contest-table/contest_table_provider.js';
 
 /**
  * Store that manages the active contest type selection.
diff --git a/src/features/tasks/utils/contest-table/aalc_provider.ts b/src/features/tasks/utils/contest-table/aalc_provider.ts
index 77fc6d6cd..da7d6ca44 100644
--- a/src/features/tasks/utils/contest-table/aalc_provider.ts
+++ b/src/features/tasks/utils/contest-table/aalc_provider.ts
@@ -1,7 +1,7 @@
 import {
   type ContestTableMetaData,
   type ContestTableDisplayConfig,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 import type { TaskResult } from '#lib/types/task.js';
 
 import { classifyContest } from '#lib/contests/index.js';
diff --git a/src/features/tasks/utils/contest-table/abc_providers.test.ts b/src/features/tasks/utils/contest-table/abc_providers.test.ts
index 42834bc2d..ddb6a9d86 100644
--- a/src/features/tasks/utils/contest-table/abc_providers.test.ts
+++ b/src/features/tasks/utils/contest-table/abc_providers.test.ts
@@ -11,7 +11,7 @@ import {
   ABC001ToABC041Provider,
 } from './abc_providers';
 import { parseContestRound } from './contest_table_provider_base';
-import { taskResultsForContestTableProvider } from '$features/tasks/fixtures/contest-table/contest_table_provider';
+import { taskResultsForContestTableProvider } from '#features/tasks/fixtures/contest-table/contest_table_provider.js';
 
 describe('ABC providers', () => {
   const mockTaskResults: TaskResults = taskResultsForContestTableProvider;
diff --git a/src/features/tasks/utils/contest-table/abc_providers.ts b/src/features/tasks/utils/contest-table/abc_providers.ts
index 9cac83b2d..9ac90732c 100644
--- a/src/features/tasks/utils/contest-table/abc_providers.ts
+++ b/src/features/tasks/utils/contest-table/abc_providers.ts
@@ -1,7 +1,7 @@
 import {
   type ContestTableMetaData,
   type ContestTableDisplayConfig,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 import type { TaskResult } from '#lib/types/task.js';
 
 import { classifyContest, getContestNameLabel } from '#lib/contests/index.js';
diff --git a/src/features/tasks/utils/contest-table/abs_provider.test.ts b/src/features/tasks/utils/contest-table/abs_provider.test.ts
index 9e196dec4..a61ce8aed 100644
--- a/src/features/tasks/utils/contest-table/abs_provider.test.ts
+++ b/src/features/tasks/utils/contest-table/abs_provider.test.ts
@@ -4,7 +4,7 @@ import { ContestType } from '#lib/contests/types/contest.js';
 import type { TaskResults } from '#lib/types/task.js';
 
 import { ABSProvider } from './abs_provider';
-import { taskResultsForABS } from '$features/tasks/fixtures/contest-table/contest_table_provider';
+import { taskResultsForABS } from '#features/tasks/fixtures/contest-table/contest_table_provider.js';
 
 describe('ABSProvider', () => {
   describe('ABS', () => {
diff --git a/src/features/tasks/utils/contest-table/abs_provider.ts b/src/features/tasks/utils/contest-table/abs_provider.ts
index 5028956da..226083aa5 100644
--- a/src/features/tasks/utils/contest-table/abs_provider.ts
+++ b/src/features/tasks/utils/contest-table/abs_provider.ts
@@ -1,7 +1,7 @@
 import {
   type ContestTableMetaData,
   type ContestTableDisplayConfig,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 import type { TaskResult } from '#lib/types/task.js';
 
 import { classifyContest } from '#lib/contests/index.js';
diff --git a/src/features/tasks/utils/contest-table/acl_providers.test.ts b/src/features/tasks/utils/contest-table/acl_providers.test.ts
index 4efb0845d..9cc831f68 100644
--- a/src/features/tasks/utils/contest-table/acl_providers.test.ts
+++ b/src/features/tasks/utils/contest-table/acl_providers.test.ts
@@ -9,7 +9,7 @@ import {
   taskResultsForACLBeginnerProvider,
   taskResultsForACLProvider,
   taskResultsForContestTableProvider,
-} from '$features/tasks/fixtures/contest-table/contest_table_provider';
+} from '#features/tasks/fixtures/contest-table/contest_table_provider.js';
 
 describe('ACLPracticeProvider', () => {
   test('expects to filter tasks with contest_id "practice2"', () => {
diff --git a/src/features/tasks/utils/contest-table/acl_providers.ts b/src/features/tasks/utils/contest-table/acl_providers.ts
index 8179d0197..ffed82294 100644
--- a/src/features/tasks/utils/contest-table/acl_providers.ts
+++ b/src/features/tasks/utils/contest-table/acl_providers.ts
@@ -1,7 +1,7 @@
 import {
   type ContestTableMetaData,
   type ContestTableDisplayConfig,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 import type { TaskResult } from '#lib/types/task.js';
 
 import { classifyContest } from '#lib/contests/index.js';
diff --git a/src/features/tasks/utils/contest-table/agc_provider.test.ts b/src/features/tasks/utils/contest-table/agc_provider.test.ts
index d3e1f82a8..0d255fbb4 100644
--- a/src/features/tasks/utils/contest-table/agc_provider.test.ts
+++ b/src/features/tasks/utils/contest-table/agc_provider.test.ts
@@ -5,7 +5,7 @@ import type { TaskResults } from '#lib/types/task.js';
 
 import { AGC001OnwardsProvider } from './agc_provider';
 import { parseContestRound } from './contest_table_provider_base';
-import { taskResultsForAGC001OnwardsProvider } from '$features/tasks/fixtures/contest-table/contest_table_provider';
+import { taskResultsForAGC001OnwardsProvider } from '#features/tasks/fixtures/contest-table/contest_table_provider.js';
 
 describe('AGC001OnwardsProvider', () => {
   test('expects to filter tasks to include only AGC001 and later', () => {
diff --git a/src/features/tasks/utils/contest-table/agc_provider.ts b/src/features/tasks/utils/contest-table/agc_provider.ts
index 318768476..ceeaf18f9 100644
--- a/src/features/tasks/utils/contest-table/agc_provider.ts
+++ b/src/features/tasks/utils/contest-table/agc_provider.ts
@@ -1,4 +1,4 @@
-import { type ContestTableMetaData } from '$features/tasks/types/contest-table/contest_table_provider';
+import { type ContestTableMetaData } from '#features/tasks/types/contest-table/contest_table_provider.js';
 import type { TaskResult } from '#lib/types/task.js';
 
 import { classifyContest, getContestNameLabel } from '#lib/contests/index.js';
diff --git a/src/features/tasks/utils/contest-table/aoj_icpc_providers.ts b/src/features/tasks/utils/contest-table/aoj_icpc_providers.ts
index cda8b32a6..047ff48c4 100644
--- a/src/features/tasks/utils/contest-table/aoj_icpc_providers.ts
+++ b/src/features/tasks/utils/contest-table/aoj_icpc_providers.ts
@@ -3,7 +3,7 @@ import type { TaskResult, TaskResults } from '#lib/types/task.js';
 import {
   type ContestTableMetaData,
   type ContestTableDisplayConfig,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 
 import { ContestTableProviderBase } from './contest_table_provider_base';
 import {
diff --git a/src/features/tasks/utils/contest-table/aoj_jag_providers.ts b/src/features/tasks/utils/contest-table/aoj_jag_providers.ts
index 7f0aa5e73..851452124 100644
--- a/src/features/tasks/utils/contest-table/aoj_jag_providers.ts
+++ b/src/features/tasks/utils/contest-table/aoj_jag_providers.ts
@@ -3,7 +3,7 @@ import type { TaskResult, TaskResults } from '#lib/types/task.js';
 import {
   type ContestTableMetaData,
   type ContestTableDisplayConfig,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 
 import { ContestTableProviderBase } from './contest_table_provider_base';
 import {
diff --git a/src/features/tasks/utils/contest-table/aoj_labels.ts b/src/features/tasks/utils/contest-table/aoj_labels.ts
index 7e28bd0b2..2a1d6e7f5 100644
--- a/src/features/tasks/utils/contest-table/aoj_labels.ts
+++ b/src/features/tasks/utils/contest-table/aoj_labels.ts
@@ -2,7 +2,7 @@ import type { TaskResults } from '#lib/types/task.js';
 import type {
   ContestTableDisplayConfig,
   ContestTableTitleStyle,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 
 // contest_id -> (task_table_index -> letter). Used only for years with judge gaps.
 // Keyed by full contest_id so AOJ contests (ICPC, JAG) can share one map.
diff --git a/src/features/tasks/utils/contest-table/arc_providers.test.ts b/src/features/tasks/utils/contest-table/arc_providers.test.ts
index 3c42c148b..d1b2b572f 100644
--- a/src/features/tasks/utils/contest-table/arc_providers.test.ts
+++ b/src/features/tasks/utils/contest-table/arc_providers.test.ts
@@ -9,7 +9,7 @@ import {
   ARC001ToARC057Provider,
 } from './arc_providers';
 import { parseContestRound } from './contest_table_provider_base';
-import { taskResultsForARC104OnwardsProvider } from '$features/tasks/fixtures/contest-table/contest_table_provider';
+import { taskResultsForARC104OnwardsProvider } from '#features/tasks/fixtures/contest-table/contest_table_provider.js';
 
 describe('ARC providers', () => {
   // ARC 104 Onwards only
diff --git a/src/features/tasks/utils/contest-table/arc_providers.ts b/src/features/tasks/utils/contest-table/arc_providers.ts
index c3c613716..3c5d5a499 100644
--- a/src/features/tasks/utils/contest-table/arc_providers.ts
+++ b/src/features/tasks/utils/contest-table/arc_providers.ts
@@ -1,7 +1,7 @@
 import {
   type ContestTableMetaData,
   type ContestTableDisplayConfig,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 import type { TaskResult } from '#lib/types/task.js';
 
 import { classifyContest, getContestNameLabel } from '#lib/contests/index.js';
diff --git a/src/features/tasks/utils/contest-table/awc_provider.test.ts b/src/features/tasks/utils/contest-table/awc_provider.test.ts
index 8415752e5..820c51e31 100644
--- a/src/features/tasks/utils/contest-table/awc_provider.test.ts
+++ b/src/features/tasks/utils/contest-table/awc_provider.test.ts
@@ -10,7 +10,7 @@ import {
   taskResultsForAWC0101To0149Provider,
   taskResultsForAWC0150Provider,
   taskResultsForAWC0151OnwardsProvider,
-} from '$features/tasks/fixtures/contest-table/contest_table_provider';
+} from '#features/tasks/fixtures/contest-table/contest_table_provider.js';
 
 const allAWCTaskResults: TaskResults = [
   ...taskResultsForAWC0001To0099Provider,
diff --git a/src/features/tasks/utils/contest-table/awc_provider.ts b/src/features/tasks/utils/contest-table/awc_provider.ts
index 39c554b4d..fc2502afd 100644
--- a/src/features/tasks/utils/contest-table/awc_provider.ts
+++ b/src/features/tasks/utils/contest-table/awc_provider.ts
@@ -1,7 +1,7 @@
 import {
   type ContestTableMetaData,
   type ContestTableDisplayConfig,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 import { ContestType } from '#lib/contests/types/contest.js';
 import type { TaskResult } from '#lib/types/task.js';
 
diff --git a/src/features/tasks/utils/contest-table/axc_like_provider.test.ts b/src/features/tasks/utils/contest-table/axc_like_provider.test.ts
index 999a1c9af..620f3e655 100644
--- a/src/features/tasks/utils/contest-table/axc_like_provider.test.ts
+++ b/src/features/tasks/utils/contest-table/axc_like_provider.test.ts
@@ -4,7 +4,7 @@ import { ContestType } from '#lib/contests/types/contest.js';
 import type { TaskResults } from '#lib/types/task.js';
 
 import { ABCLikeProvider } from './axc_like_provider';
-import { taskResultsForABCLikeProvider } from '$features/tasks/fixtures/contest-table/contest_table_provider';
+import { taskResultsForABCLikeProvider } from '#features/tasks/fixtures/contest-table/contest_table_provider.js';
 
 describe('ABCLikeProvider', () => {
   test('expects to filter tasks to include only ABC-Like contests', () => {
diff --git a/src/features/tasks/utils/contest-table/axc_like_provider.ts b/src/features/tasks/utils/contest-table/axc_like_provider.ts
index 488764d23..40304ece8 100644
--- a/src/features/tasks/utils/contest-table/axc_like_provider.ts
+++ b/src/features/tasks/utils/contest-table/axc_like_provider.ts
@@ -1,7 +1,7 @@
 import {
   type ContestTableMetaData,
   type ContestTableDisplayConfig,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 import type { TaskResult } from '#lib/types/task.js';
 
 import { classifyContest } from '#lib/contests/index.js';
diff --git a/src/features/tasks/utils/contest-table/contest_table_provider_base.test.ts b/src/features/tasks/utils/contest-table/contest_table_provider_base.test.ts
index a2c407175..a24770c29 100644
--- a/src/features/tasks/utils/contest-table/contest_table_provider_base.test.ts
+++ b/src/features/tasks/utils/contest-table/contest_table_provider_base.test.ts
@@ -3,7 +3,7 @@ import { describe, test, expect } from 'vitest';
 import { ContestType } from '#lib/contests/types/contest.js';
 
 import { ABSProvider } from './contest_table_provider';
-import { taskResultsForABS } from '$features/tasks/fixtures/contest-table/contest_table_provider';
+import { taskResultsForABS } from '#features/tasks/fixtures/contest-table/contest_table_provider.js';
 
 describe('ContestTableProviderBase', () => {
   describe('Common provider functionality', () => {
diff --git a/src/features/tasks/utils/contest-table/contest_table_provider_base.ts b/src/features/tasks/utils/contest-table/contest_table_provider_base.ts
index 7adf4a769..18cd16165 100644
--- a/src/features/tasks/utils/contest-table/contest_table_provider_base.ts
+++ b/src/features/tasks/utils/contest-table/contest_table_provider_base.ts
@@ -4,7 +4,7 @@ import {
   type ContestTableMetaData,
   type ContestTableDisplayConfig,
   type ProviderKey,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 import { ContestType } from '#lib/contests/types/contest.js';
 import type { TaskResults, TaskResult } from '#lib/types/task.js';
 
diff --git a/src/features/tasks/utils/contest-table/contest_table_provider_group.test.ts b/src/features/tasks/utils/contest-table/contest_table_provider_group.test.ts
index 9d48662b3..32399ecc7 100644
--- a/src/features/tasks/utils/contest-table/contest_table_provider_group.test.ts
+++ b/src/features/tasks/utils/contest-table/contest_table_provider_group.test.ts
@@ -7,7 +7,7 @@ import {
   ContestTableProviderBase,
   ContestTableProviderGroup,
 } from './contest_table_provider';
-import { TESSOKU_SECTIONS } from '$features/tasks/types/contest-table/contest_table_provider';
+import { TESSOKU_SECTIONS } from '#features/tasks/types/contest-table/contest_table_provider.js';
 import { EDPCProvider, TDPCProvider } from './dp_providers';
 import {
   TessokuBookForExamplesProvider,
diff --git a/src/features/tasks/utils/contest-table/contest_table_provider_group.ts b/src/features/tasks/utils/contest-table/contest_table_provider_group.ts
index 3b8cc32e2..f0c11e36d 100644
--- a/src/features/tasks/utils/contest-table/contest_table_provider_group.ts
+++ b/src/features/tasks/utils/contest-table/contest_table_provider_group.ts
@@ -1,4 +1,4 @@
-import { type ContestTablesMetaData } from '$features/tasks/types/contest-table/contest_table_provider';
+import { type ContestTablesMetaData } from '#features/tasks/types/contest-table/contest_table_provider.js';
 import { ContestType } from '#lib/contests/types/contest.js';
 
 import { ContestTableProviderBase } from './contest_table_provider_base';
diff --git a/src/features/tasks/utils/contest-table/contest_table_provider_groups.test.ts b/src/features/tasks/utils/contest-table/contest_table_provider_groups.test.ts
index c1c6e70c3..ce604c9e1 100644
--- a/src/features/tasks/utils/contest-table/contest_table_provider_groups.test.ts
+++ b/src/features/tasks/utils/contest-table/contest_table_provider_groups.test.ts
@@ -2,7 +2,7 @@ import { describe, test, expect } from 'vitest';
 
 import { ContestType } from '#lib/contests/types/contest.js';
 
-import { TESSOKU_SECTIONS } from '$features/tasks/types/contest-table/contest_table_provider';
+import { TESSOKU_SECTIONS } from '#features/tasks/types/contest-table/contest_table_provider.js';
 
 import {
   ICPC_PRELIM_OLDEST_YEAR,
diff --git a/src/features/tasks/utils/contest-table/dp_providers.ts b/src/features/tasks/utils/contest-table/dp_providers.ts
index a74b2b0a8..688673e30 100644
--- a/src/features/tasks/utils/contest-table/dp_providers.ts
+++ b/src/features/tasks/utils/contest-table/dp_providers.ts
@@ -1,7 +1,7 @@
 import {
   type ContestTableMetaData,
   type ContestTableDisplayConfig,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 import type { TaskResult } from '#lib/types/task.js';
 
 import { classifyContest } from '#lib/contests/index.js';
diff --git a/src/features/tasks/utils/contest-table/fps24_provider.ts b/src/features/tasks/utils/contest-table/fps24_provider.ts
index 0234d0b8c..83ed60329 100644
--- a/src/features/tasks/utils/contest-table/fps24_provider.ts
+++ b/src/features/tasks/utils/contest-table/fps24_provider.ts
@@ -1,7 +1,7 @@
 import {
   type ContestTableMetaData,
   type ContestTableDisplayConfig,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 import type { TaskResult } from '#lib/types/task.js';
 
 import { classifyContest } from '#lib/contests/index.js';
diff --git a/src/features/tasks/utils/contest-table/game24_provider.ts b/src/features/tasks/utils/contest-table/game24_provider.ts
index 18a5451a1..42520f3ec 100644
--- a/src/features/tasks/utils/contest-table/game24_provider.ts
+++ b/src/features/tasks/utils/contest-table/game24_provider.ts
@@ -1,7 +1,7 @@
 import {
   type ContestTableMetaData,
   type ContestTableDisplayConfig,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 import type { TaskResult } from '#lib/types/task.js';
 
 import { classifyContest } from '#lib/contests/index.js';
diff --git a/src/features/tasks/utils/contest-table/joi_providers.ts b/src/features/tasks/utils/contest-table/joi_providers.ts
index b1f68475b..6403152fb 100644
--- a/src/features/tasks/utils/contest-table/joi_providers.ts
+++ b/src/features/tasks/utils/contest-table/joi_providers.ts
@@ -3,7 +3,7 @@ import {
   type ContestTableDisplayConfig,
   JOI_SECOND_QUAL_ROUND_SECTIONS,
   JOI_FINAL_ROUND_SECTIONS,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 import { ContestType } from '#lib/contests/types/contest.js';
 import type { TaskResult } from '#lib/types/task.js';
 
diff --git a/src/features/tasks/utils/contest-table/math_and_algorithm_provider.ts b/src/features/tasks/utils/contest-table/math_and_algorithm_provider.ts
index 959944d93..9ce5e55ca 100644
--- a/src/features/tasks/utils/contest-table/math_and_algorithm_provider.ts
+++ b/src/features/tasks/utils/contest-table/math_and_algorithm_provider.ts
@@ -1,7 +1,7 @@
 import {
   type ContestTableMetaData,
   type ContestTableDisplayConfig,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 import type { TaskResult } from '#lib/types/task.js';
 
 import { classifyContest } from '#lib/contests/index.js';
diff --git a/src/features/tasks/utils/contest-table/tessoku_book_providers.ts b/src/features/tasks/utils/contest-table/tessoku_book_providers.ts
index 2f75eb3d7..aef721c1f 100644
--- a/src/features/tasks/utils/contest-table/tessoku_book_providers.ts
+++ b/src/features/tasks/utils/contest-table/tessoku_book_providers.ts
@@ -2,7 +2,7 @@ import {
   type ContestTableMetaData,
   type ContestTableDisplayConfig,
   TESSOKU_SECTIONS,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 import { ContestType } from '#lib/contests/types/contest.js';
 import type { TaskResult } from '#lib/types/task.js';
 
diff --git a/src/features/tasks/utils/contest-table/typical90_provider.test.ts b/src/features/tasks/utils/contest-table/typical90_provider.test.ts
index 7c814bc5f..9c7258f6c 100644
--- a/src/features/tasks/utils/contest-table/typical90_provider.test.ts
+++ b/src/features/tasks/utils/contest-table/typical90_provider.test.ts
@@ -4,7 +4,7 @@ import { ContestType } from '#lib/contests/types/contest.js';
 import type { TaskResults } from '#lib/types/task.js';
 
 import { Typical90Provider } from './typical90_provider';
-import { taskResultsForContestTableProvider } from '$features/tasks/fixtures/contest-table/contest_table_provider';
+import { taskResultsForContestTableProvider } from '#features/tasks/fixtures/contest-table/contest_table_provider.js';
 
 describe('Typical90Provider', () => {
   const mockTaskResults: TaskResults = taskResultsForContestTableProvider;
diff --git a/src/features/tasks/utils/contest-table/typical90_provider.ts b/src/features/tasks/utils/contest-table/typical90_provider.ts
index 08650fd3c..ad8ba1e79 100644
--- a/src/features/tasks/utils/contest-table/typical90_provider.ts
+++ b/src/features/tasks/utils/contest-table/typical90_provider.ts
@@ -1,7 +1,7 @@
 import {
   type ContestTableMetaData,
   type ContestTableDisplayConfig,
-} from '$features/tasks/types/contest-table/contest_table_provider';
+} from '#features/tasks/types/contest-table/contest_table_provider.js';
 import type { TaskResult } from '#lib/types/task.js';
 
 import { classifyContest } from '#lib/contests/index.js';
diff --git a/src/features/votes/actions/vote_actions.ts b/src/features/votes/actions/vote_actions.ts
index 1698977c4..5f8acfa83 100644
--- a/src/features/votes/actions/vote_actions.ts
+++ b/src/features/votes/actions/vote_actions.ts
@@ -1,14 +1,14 @@
 import { fail } from '@sveltejs/kit';
 import type { TaskGrade } from '@prisma/client';
 
-import { upsertVoteGradeTables } from '$features/votes/services/vote_grade';
+import { upsertVoteGradeTables } from '#features/votes/services/vote_grade.js';
 import {
   FORBIDDEN,
   INTERNAL_SERVER_ERROR,
   UNAUTHORIZED,
 } from '#lib/constants/http-response-status-codes.js';
 
-import type { VoteAbsoluteGradeInput } from '$features/votes/zod/schema';
+import type { VoteAbsoluteGradeInput } from '#features/votes/zod/schema.js';
 
 export const voteAbsoluteGrade = async ({
   locals,
diff --git a/src/features/votes/components/RelativeEvaluationBadge.svelte b/src/features/votes/components/RelativeEvaluationBadge.svelte
index 354def55d..a00bfc530 100644
--- a/src/features/votes/components/RelativeEvaluationBadge.svelte
+++ b/src/features/votes/components/RelativeEvaluationBadge.svelte
@@ -7,7 +7,7 @@
     getRelativeEvaluationLabel,
     getRelativeEvaluationTooltipText,
     getRelativeEvaluationBadgeColorClass,
-  } from '$features/votes/utils/relative_evaluation';
+  } from '#features/votes/utils/relative_evaluation.js';
 
   interface Props {
     officialGrade: TaskGrade;
diff --git a/src/features/votes/components/VotableGrade.svelte b/src/features/votes/components/VotableGrade.svelte
index d40cfe2ca..f92442054 100644
--- a/src/features/votes/components/VotableGrade.svelte
+++ b/src/features/votes/components/VotableGrade.svelte
@@ -13,22 +13,22 @@
     fetchMyVote,
     submitVote,
     fetchMedianVote,
-  } from '$features/votes/internal_clients/vote_grade';
+  } from '#features/votes/internal_clients/vote_grade.js';
 
   import { getTaskGradeLabel } from '#lib/utils/task.js';
-  import { nonPendingGrades, resolveDisplayGrade } from '$features/votes/utils/grade_options';
-  import { calcCenteredScrollTop } from '$features/votes/utils/grade_scroll_position';
+  import { nonPendingGrades, resolveDisplayGrade } from '#features/votes/utils/grade_options.js';
+  import { calcCenteredScrollTop } from '#features/votes/utils/grade_scroll_position.js';
   import {
     calcGradeDiff,
     getRelativeEvaluationLabel,
     getRelativeEvaluationJapaneseLabel,
     getRelativeEvaluationColorClass,
-  } from '$features/votes/utils/relative_evaluation';
+  } from '#features/votes/utils/relative_evaluation.js';
   import { SIGNUP_PAGE, LOGIN_PAGE, EDIT_PROFILE_PAGE } from '#lib/constants/navbar-links.js';
 
   import GradeLabel from '#lib/components/GradeLabel.svelte';
   import InputFieldWrapper from '#lib/components/InputFieldWrapper.svelte';
-  import RelativeEvaluationBadge from '$features/votes/components/RelativeEvaluationBadge.svelte';
+  import RelativeEvaluationBadge from '#features/votes/components/RelativeEvaluationBadge.svelte';
 
   interface Props {
     taskResult: TaskResult;
diff --git a/src/features/votes/components/VoteDonutChart.svelte b/src/features/votes/components/VoteDonutChart.svelte
index b44473904..5e8d733b6 100644
--- a/src/features/votes/components/VoteDonutChart.svelte
+++ b/src/features/votes/components/VoteDonutChart.svelte
@@ -1,15 +1,15 @@
 <script lang="ts">
   import type { VotedGradeCounter } from '@prisma/client';
   import { TaskGrade } from '#lib/types/task.js';
-  import type { DonutSegment } from '$features/votes/types/donut_graph';
+  import type { DonutSegment } from '#features/votes/types/donut_graph.js';
 
   import { getTaskGradeColor, getTaskGradeLabel } from '#lib/utils/task.js';
-  import { nonPendingGrades } from '$features/votes/utils/grade_options';
+  import { nonPendingGrades } from '#features/votes/utils/grade_options.js';
   import {
     buildDonutSegments,
     buildArcPath,
     calcPointOnCircle,
-  } from '$features/votes/utils/donut_chart';
+  } from '#features/votes/utils/donut_chart.js';
 
   type VotedGradeCounters = VotedGradeCounter[];
 
diff --git a/src/features/votes/server/cache.test.ts b/src/features/votes/server/cache.test.ts
index 7e8440e43..863037a62 100644
--- a/src/features/votes/server/cache.test.ts
+++ b/src/features/votes/server/cache.test.ts
@@ -2,7 +2,7 @@ import { describe, test, expect, vi, beforeEach, afterEach, afterAll } from 'vit
 
 import type { VotedGradeStatistics } from '@prisma/client';
 import { TaskGrade } from '#lib/types/task.js';
-import type { TaskWithVoteInfo } from '$features/votes/services/vote_statistics';
+import type { TaskWithVoteInfo } from '#features/votes/services/vote_statistics.js';
 import {
   getCachedVoteStats,
   getCachedAllTasksWithVoteInfo,
diff --git a/src/features/votes/server/cache.ts b/src/features/votes/server/cache.ts
index c3b69f0b8..535077295 100644
--- a/src/features/votes/server/cache.ts
+++ b/src/features/votes/server/cache.ts
@@ -2,7 +2,7 @@ import { Cache } from '#lib/clients/cache.js';
 
 import type { VotedGradeStatistics } from '@prisma/client';
 
-import type { TaskWithVoteInfo } from '$features/votes/services/vote_statistics';
+import type { TaskWithVoteInfo } from '#features/votes/services/vote_statistics.js';
 
 const VOTE_STATS_TTL_MS = 10 * 60 * 1000;
 const VOTE_STATS_KEY = 'vote_grade_statistics';
diff --git a/src/features/votes/services/vote_grade.test.ts b/src/features/votes/services/vote_grade.test.ts
index 5aba00e6a..7ccb83a10 100644
--- a/src/features/votes/services/vote_grade.test.ts
+++ b/src/features/votes/services/vote_grade.test.ts
@@ -4,7 +4,7 @@ import { TaskGrade } from '@prisma/client';
 
 import { getVoteGrade, upsertVoteGradeTables } from './vote_grade';
 
-vi.mock('$features/votes/server/cache', () => ({
+vi.mock('#features/votes/server/cache.js', () => ({
   invalidateVoteCaches: vi.fn(),
 }));
 
@@ -30,7 +30,7 @@ vi.mock('#lib/server/database.js', () => ({
 }));
 
 import prisma from '#lib/server/database.js';
-import { invalidateVoteCaches } from '$features/votes/server/cache';
+import { invalidateVoteCaches } from '#features/votes/server/cache.js';
 
 // ---------------------------------------------------------------------------
 // Type aliases
diff --git a/src/features/votes/services/vote_grade.ts b/src/features/votes/services/vote_grade.ts
index adec87c04..c2e87dd9e 100644
--- a/src/features/votes/services/vote_grade.ts
+++ b/src/features/votes/services/vote_grade.ts
@@ -1,13 +1,13 @@
 import { default as prisma } from '#lib/server/database.js';
 import { TaskGrade } from '@prisma/client';
 import { sha256 } from '#lib/utils/hash.js';
-import type { VoteGradeResult } from '$features/votes/types/vote_result';
-import { computeMedianGrade } from '$features/votes/utils/median';
+import type { VoteGradeResult } from '#features/votes/types/vote_result.js';
+import { computeMedianGrade } from '#features/votes/utils/median.js';
 import {
   MIN_VOTES_FOR_STATISTICS,
   MIN_VOTES_FOR_PROVISIONAL_GRADE,
-} from '$features/votes/constants/statistics';
-import { invalidateVoteCaches } from '$features/votes/server/cache';
+} from '#features/votes/constants/statistics.js';
+import { invalidateVoteCaches } from '#features/votes/server/cache.js';
 
 export async function getVoteGrade(userId: string, taskId: string): Promise<VoteGradeResult> {
   const voteRecord = await prisma.voteGrade.findUnique({
diff --git a/src/features/votes/services/vote_statistics.test.ts b/src/features/votes/services/vote_statistics.test.ts
index 8f05c383c..d07ca816a 100644
--- a/src/features/votes/services/vote_statistics.test.ts
+++ b/src/features/votes/services/vote_statistics.test.ts
@@ -30,7 +30,7 @@ vi.mock('#lib/server/database.js', () => ({
   },
 }));
 
-vi.mock('$features/votes/server/cache', () => ({
+vi.mock('#features/votes/server/cache.js', () => ({
   getCachedVoteStats: (fetchFn: () => Promise<unknown>) => fetchFn(),
   getCachedAllTasksWithVoteInfo: (fetchFn: () => Promise<unknown>) => fetchFn(),
 }));
diff --git a/src/features/votes/services/vote_statistics.ts b/src/features/votes/services/vote_statistics.ts
index e12ce19dd..bebf77395 100644
--- a/src/features/votes/services/vote_statistics.ts
+++ b/src/features/votes/services/vote_statistics.ts
@@ -1,5 +1,5 @@
 import { default as prisma } from '#lib/server/database.js';
-import { getCachedVoteStats, getCachedAllTasksWithVoteInfo } from '$features/votes/server/cache';
+import { getCachedVoteStats, getCachedAllTasksWithVoteInfo } from '#features/votes/server/cache.js';
 
 import type { VotedGradeStatistics, VotedGradeCounter, TaskGrade } from '@prisma/client';
 
diff --git a/src/features/votes/utils/donut_chart.ts b/src/features/votes/utils/donut_chart.ts
index e2765806d..461691d80 100644
--- a/src/features/votes/utils/donut_chart.ts
+++ b/src/features/votes/utils/donut_chart.ts
@@ -1,5 +1,5 @@
 import { TaskGrade } from '#lib/types/task.js';
-import type { DonutSegment, DonutSegments } from '$features/votes/types/donut_graph';
+import type { DonutSegment, DonutSegments } from '#features/votes/types/donut_graph.js';
 
 export type { DonutSegment, DonutSegments };
 
diff --git a/src/features/votes/utils/median.ts b/src/features/votes/utils/median.ts
index ef1e3d1b4..b3db5bd29 100644
--- a/src/features/votes/utils/median.ts
+++ b/src/features/votes/utils/median.ts
@@ -1,6 +1,6 @@
 import { TaskGrade } from '@prisma/client';
 import { getGradeOrder, taskGradeOrderInfinity } from '#lib/utils/task.js';
-import { MIN_VOTES_FOR_STATISTICS } from '$features/votes/constants/statistics';
+import { MIN_VOTES_FOR_STATISTICS } from '#features/votes/constants/statistics.js';
 
 /** Maps grade order (1=Q11 … 17=D6) back to the corresponding TaskGrade enum value. */
 const ORDER_TO_TASK_GRADE: Map<number, TaskGrade> = new Map([
diff --git a/src/features/votes/zod/schema.test.ts b/src/features/votes/zod/schema.test.ts
index b975e7d58..f1f29fc39 100644
--- a/src/features/votes/zod/schema.test.ts
+++ b/src/features/votes/zod/schema.test.ts
@@ -1,7 +1,7 @@
 import { describe, expect, test } from 'vitest';
 import { TaskGrade } from '@prisma/client';
 
-import { voteAbsoluteGradeSchema } from '$features/votes/zod/schema';
+import { voteAbsoluteGradeSchema } from '#features/votes/zod/schema.js';
 
 describe('voteAbsoluteGradeSchema', () => {
   function validate(data: unknown): boolean {
diff --git a/src/features/workbooks/components/detail/WorkBookTasksTable.svelte b/src/features/workbooks/components/detail/WorkBookTasksTable.svelte
index c8d4630c5..e79245e40 100644
--- a/src/features/workbooks/components/detail/WorkBookTasksTable.svelte
+++ b/src/features/workbooks/components/detail/WorkBookTasksTable.svelte
@@ -24,7 +24,7 @@
     WorkBookTaskCreate,
     WorkBookTasksEdit,
     WorkBookTaskEdit,
-  } from '$features/workbooks/types/workbook';
+  } from '#features/workbooks/types/workbook.js';
   import type { Task } from '#lib/types/task.js';
 
   interface Props {
diff --git a/src/features/workbooks/components/list/AcceptedCounter.svelte b/src/features/workbooks/components/list/AcceptedCounter.svelte
index 876750f5c..cf1acac8a 100644
--- a/src/features/workbooks/components/list/AcceptedCounter.svelte
+++ b/src/features/workbooks/components/list/AcceptedCounter.svelte
@@ -1,6 +1,6 @@
 <script lang="ts">
   import type { TaskResults } from '#lib/types/task.js';
-  import type { WorkBookTaskBase } from '$features/workbooks/types/workbook';
+  import type { WorkBookTaskBase } from '#features/workbooks/types/workbook.js';
 
   import AcceptedCounter from '#lib/components/SubmissionStatus/AcceptedCounter.svelte';
 
diff --git a/src/features/workbooks/components/list/CreatedByUserTable.svelte b/src/features/workbooks/components/list/CreatedByUserTable.svelte
index 3b5a170bf..1a7bae4e5 100644
--- a/src/features/workbooks/components/list/CreatedByUserTable.svelte
+++ b/src/features/workbooks/components/list/CreatedByUserTable.svelte
@@ -8,17 +8,17 @@
     TableHeadCell,
   } from 'flowbite-svelte';
 
-  import type { SolutionTableProps } from '$features/workbooks/types/workbook';
+  import type { SolutionTableProps } from '#features/workbooks/types/workbook.js';
 
-  import TitleTableHeadCell from '$features/workbooks/components/list/TitleTableHeadCell.svelte';
-  import TitleTableBodyCell from '$features/workbooks/components/list/TitleTableBodyCell.svelte';
-  import WorkbookProgressCell from '$features/workbooks/components/list/WorkbookProgressCell.svelte';
-  import WorkbookCompletionCell from '$features/workbooks/components/list/WorkbookCompletionCell.svelte';
-  import WorkbookAuthorActionsCell from '$features/workbooks/components/list/WorkbookAuthorActionsCell.svelte';
-  import EmptyWorkbookList from '$features/workbooks/components/list/EmptyWorkbookList.svelte';
+  import TitleTableHeadCell from '#features/workbooks/components/list/TitleTableHeadCell.svelte';
+  import TitleTableBodyCell from '#features/workbooks/components/list/TitleTableBodyCell.svelte';
+  import WorkbookProgressCell from '#features/workbooks/components/list/WorkbookProgressCell.svelte';
+  import WorkbookCompletionCell from '#features/workbooks/components/list/WorkbookCompletionCell.svelte';
+  import WorkbookAuthorActionsCell from '#features/workbooks/components/list/WorkbookAuthorActionsCell.svelte';
+  import EmptyWorkbookList from '#features/workbooks/components/list/EmptyWorkbookList.svelte';
 
   import { canRead } from '#lib/utils/authorship.js';
-  import { getTaskResult } from '$features/workbooks/utils/workbooks';
+  import { getTaskResult } from '#features/workbooks/utils/workbooks.js';
 
   let { workbooks, userId, role, taskResults }: SolutionTableProps = $props();
 
diff --git a/src/features/workbooks/components/list/CurriculumTable.svelte b/src/features/workbooks/components/list/CurriculumTable.svelte
index 33c70bda0..71d3cde9c 100644
--- a/src/features/workbooks/components/list/CurriculumTable.svelte
+++ b/src/features/workbooks/components/list/CurriculumTable.svelte
@@ -1,17 +1,17 @@
 <script lang="ts">
   import { Table, TableBody, TableBodyRow, TableHead, TableHeadCell } from 'flowbite-svelte';
 
-  import type { WorkbookTableProps } from '$features/workbooks/types/workbook';
+  import type { WorkbookTableProps } from '#features/workbooks/types/workbook.js';
 
-  import TitleTableHeadCell from '$features/workbooks/components/list/TitleTableHeadCell.svelte';
-  import TitleTableBodyCell from '$features/workbooks/components/list/TitleTableBodyCell.svelte';
-  import GradeTableBodyCell from '$features/workbooks/components/list/GradeTableBodyCell.svelte';
-  import WorkbookProgressCell from '$features/workbooks/components/list/WorkbookProgressCell.svelte';
-  import WorkbookCompletionCell from '$features/workbooks/components/list/WorkbookCompletionCell.svelte';
-  import WorkbookAuthorActionsCell from '$features/workbooks/components/list/WorkbookAuthorActionsCell.svelte';
+  import TitleTableHeadCell from '#features/workbooks/components/list/TitleTableHeadCell.svelte';
+  import TitleTableBodyCell from '#features/workbooks/components/list/TitleTableBodyCell.svelte';
+  import GradeTableBodyCell from '#features/workbooks/components/list/GradeTableBodyCell.svelte';
+  import WorkbookProgressCell from '#features/workbooks/components/list/WorkbookProgressCell.svelte';
+  import WorkbookCompletionCell from '#features/workbooks/components/list/WorkbookCompletionCell.svelte';
+  import WorkbookAuthorActionsCell from '#features/workbooks/components/list/WorkbookAuthorActionsCell.svelte';
 
   import { canRead } from '#lib/utils/authorship.js';
-  import { getGradeMode, getTaskResult } from '$features/workbooks/utils/workbooks';
+  import { getGradeMode, getTaskResult } from '#features/workbooks/utils/workbooks.js';
 
   let { workbooks, gradeModesEachWorkbook, userId, role, taskResults }: WorkbookTableProps =
     $props();
diff --git a/src/features/workbooks/components/list/CurriculumWorkBookList.svelte b/src/features/workbooks/components/list/CurriculumWorkBookList.svelte
index 14865ee2f..eedac25b3 100644
--- a/src/features/workbooks/components/list/CurriculumWorkBookList.svelte
+++ b/src/features/workbooks/components/list/CurriculumWorkBookList.svelte
@@ -3,20 +3,20 @@
 
   import type { Roles } from '#lib/types/user.js';
   import { TaskGrade, type TaskResults } from '#lib/types/task.js';
-  import { type WorkbooksList } from '$features/workbooks/types/workbook';
+  import { type WorkbooksList } from '#features/workbooks/types/workbook.js';
 
-  import { replenishmentWorkBooksStore } from '$features/workbooks/stores/replenishment_workbook.svelte';
+  import { replenishmentWorkBooksStore } from '#features/workbooks/stores/replenishment_workbook.svelte.js';
 
   import { getTaskGradeLabel } from '#lib/utils/task.js';
   import {
     countReadableWorkbooks,
     partitionWorkbooksAsMainAndReplenished,
-  } from '$features/workbooks/utils/workbooks';
+  } from '#features/workbooks/utils/workbooks.js';
 
   import TooltipWrapper from '#lib/components/TooltipWrapper.svelte';
   import LabelWithTooltips from '#lib/components/LabelWithTooltips.svelte';
-  import CurriculumTable from '$features/workbooks/components/list/CurriculumTable.svelte';
-  import EmptyWorkbookList from '$features/workbooks/components/list/EmptyWorkbookList.svelte';
+  import CurriculumTable from '#features/workbooks/components/list/CurriculumTable.svelte';
+  import EmptyWorkbookList from '#features/workbooks/components/list/EmptyWorkbookList.svelte';
 
   interface Props {
     workbooks: WorkbooksList;
diff --git a/src/features/workbooks/components/list/SolutionTable.svelte b/src/features/workbooks/components/list/SolutionTable.svelte
index 7bac24138..935258992 100644
--- a/src/features/workbooks/components/list/SolutionTable.svelte
+++ b/src/features/workbooks/components/list/SolutionTable.svelte
@@ -1,16 +1,16 @@
 <script lang="ts">
   import { Table, TableBody, TableBodyRow, TableHead, TableHeadCell } from 'flowbite-svelte';
 
-  import type { SolutionTableProps } from '$features/workbooks/types/workbook';
+  import type { SolutionTableProps } from '#features/workbooks/types/workbook.js';
 
-  import TitleTableHeadCell from '$features/workbooks/components/list/TitleTableHeadCell.svelte';
-  import TitleTableBodyCell from '$features/workbooks/components/list/TitleTableBodyCell.svelte';
-  import WorkbookProgressCell from '$features/workbooks/components/list/WorkbookProgressCell.svelte';
-  import WorkbookCompletionCell from '$features/workbooks/components/list/WorkbookCompletionCell.svelte';
-  import WorkbookAuthorActionsCell from '$features/workbooks/components/list/WorkbookAuthorActionsCell.svelte';
+  import TitleTableHeadCell from '#features/workbooks/components/list/TitleTableHeadCell.svelte';
+  import TitleTableBodyCell from '#features/workbooks/components/list/TitleTableBodyCell.svelte';
+  import WorkbookProgressCell from '#features/workbooks/components/list/WorkbookProgressCell.svelte';
+  import WorkbookCompletionCell from '#features/workbooks/components/list/WorkbookCompletionCell.svelte';
+  import WorkbookAuthorActionsCell from '#features/workbooks/components/list/WorkbookAuthorActionsCell.svelte';
 
   import { canRead } from '#lib/utils/authorship.js';
-  import { getTaskResult } from '$features/workbooks/utils/workbooks';
+  import { getTaskResult } from '#features/workbooks/utils/workbooks.js';
 
   let { workbooks, userId, role, taskResults }: SolutionTableProps = $props();
 </script>
diff --git a/src/features/workbooks/components/list/SolutionWorkBookList.svelte b/src/features/workbooks/components/list/SolutionWorkBookList.svelte
index d82d1a21f..64af06090 100644
--- a/src/features/workbooks/components/list/SolutionWorkBookList.svelte
+++ b/src/features/workbooks/components/list/SolutionWorkBookList.svelte
@@ -3,24 +3,24 @@
 
   import type { Roles } from '#lib/types/user.js';
   import type { TaskResults } from '#lib/types/task.js';
-  import type { WorkbooksList } from '$features/workbooks/types/workbook';
+  import type { WorkbooksList } from '#features/workbooks/types/workbook.js';
   import {
     SolutionCategory,
     type SolutionCategories,
     SOLUTION_LABELS,
     ALL_SOLUTION_CATEGORIES,
     type SelectedSolutionCategory,
-  } from '$features/workbooks/types/workbook_placement';
+  } from '#features/workbooks/types/workbook_placement.js';
 
-  import { countReadableWorkbooks } from '$features/workbooks/utils/workbooks';
+  import { countReadableWorkbooks } from '#features/workbooks/utils/workbooks.js';
   import {
     groupBySolutionCategory,
     filterGroupsByRole,
     type WorkbookGroup,
-  } from '$features/workbooks/utils/solution_category_group';
+  } from '#features/workbooks/utils/solution_category_group.js';
 
-  import SolutionTable from '$features/workbooks/components/list/SolutionTable.svelte';
-  import EmptyWorkbookList from '$features/workbooks/components/list/EmptyWorkbookList.svelte';
+  import SolutionTable from '#features/workbooks/components/list/SolutionTable.svelte';
+  import EmptyWorkbookList from '#features/workbooks/components/list/EmptyWorkbookList.svelte';
 
   interface Props {
     workbooks: WorkbooksList;
diff --git a/src/features/workbooks/components/list/TitleTableBodyCell.svelte b/src/features/workbooks/components/list/TitleTableBodyCell.svelte
index f2a747913..cedbba6eb 100644
--- a/src/features/workbooks/components/list/TitleTableBodyCell.svelte
+++ b/src/features/workbooks/components/list/TitleTableBodyCell.svelte
@@ -3,10 +3,10 @@
 
   import { TableBodyCell } from 'flowbite-svelte';
 
-  import type { WorkbookList } from '$features/workbooks/types/workbook';
+  import type { WorkbookList } from '#features/workbooks/types/workbook.js';
 
-  import { getUrlSlugFrom } from '$features/workbooks/utils/workbooks';
-  import PublicationStatusLabel from '$features/workbooks/components/shared/PublicationStatusLabel.svelte';
+  import { getUrlSlugFrom } from '#features/workbooks/utils/workbooks.js';
+  import PublicationStatusLabel from '#features/workbooks/components/shared/PublicationStatusLabel.svelte';
 
   interface Props {
     paddingLeft?: string;
diff --git a/src/features/workbooks/components/list/WorkBookList.svelte b/src/features/workbooks/components/list/WorkBookList.svelte
index 6012ed0a5..e728e6d09 100644
--- a/src/features/workbooks/components/list/WorkBookList.svelte
+++ b/src/features/workbooks/components/list/WorkBookList.svelte
@@ -1,16 +1,16 @@
 <script lang="ts">
   import { Roles } from '#lib/types/user.js';
   import { TaskGrade, type TaskResults } from '#lib/types/task.js';
-  import { WorkBookType, type WorkbooksList } from '$features/workbooks/types/workbook';
+  import { WorkBookType, type WorkbooksList } from '#features/workbooks/types/workbook.js';
   import {
     type SolutionCategory,
     type SolutionCategories,
     type SelectedSolutionCategory,
-  } from '$features/workbooks/types/workbook_placement';
+  } from '#features/workbooks/types/workbook_placement.js';
 
-  import CurriculumWorkBookList from '$features/workbooks/components/list/CurriculumWorkBookList.svelte';
-  import SolutionWorkBookList from '$features/workbooks/components/list/SolutionWorkBookList.svelte';
-  import CreatedByUserTable from '$features/workbooks/components/list/CreatedByUserTable.svelte';
+  import CurriculumWorkBookList from '#features/workbooks/components/list/CurriculumWorkBookList.svelte';
+  import SolutionWorkBookList from '#features/workbooks/components/list/SolutionWorkBookList.svelte';
+  import CreatedByUserTable from '#features/workbooks/components/list/CreatedByUserTable.svelte';
 
   type CommonProps = {
     workbooks: WorkbooksList;
diff --git a/src/features/workbooks/components/list/WorkbookAuthorActionsCell.svelte b/src/features/workbooks/components/list/WorkbookAuthorActionsCell.svelte
index d1d874a9d..7b4ad6251 100644
--- a/src/features/workbooks/components/list/WorkbookAuthorActionsCell.svelte
+++ b/src/features/workbooks/components/list/WorkbookAuthorActionsCell.svelte
@@ -5,10 +5,10 @@
   import { TableBodyCell } from 'flowbite-svelte';
 
   import type { Roles } from '#lib/types/user.js';
-  import type { WorkbookList } from '$features/workbooks/types/workbook';
+  import type { WorkbookList } from '#features/workbooks/types/workbook.js';
 
   import { canEdit, canDelete } from '#lib/utils/authorship.js';
-  import { getUrlSlugFrom } from '$features/workbooks/utils/workbooks';
+  import { getUrlSlugFrom } from '#features/workbooks/utils/workbooks.js';
 
   interface Props {
     workbook: WorkbookList;
diff --git a/src/features/workbooks/components/list/WorkbookCompletionCell.svelte b/src/features/workbooks/components/list/WorkbookCompletionCell.svelte
index 61f053436..42e37bb71 100644
--- a/src/features/workbooks/components/list/WorkbookCompletionCell.svelte
+++ b/src/features/workbooks/components/list/WorkbookCompletionCell.svelte
@@ -2,7 +2,7 @@
   import { TableBodyCell } from 'flowbite-svelte';
 
   import type { TaskResults } from '#lib/types/task.js';
-  import type { WorkBookTaskBase } from '$features/workbooks/types/workbook';
+  import type { WorkBookTaskBase } from '#features/workbooks/types/workbook.js';
 
   import CompletedTasks from '#lib/components/Trophies/CompletedTasks.svelte';
 
diff --git a/src/features/workbooks/components/list/WorkbookProgressCell.svelte b/src/features/workbooks/components/list/WorkbookProgressCell.svelte
index 15a46718b..4c60f85a4 100644
--- a/src/features/workbooks/components/list/WorkbookProgressCell.svelte
+++ b/src/features/workbooks/components/list/WorkbookProgressCell.svelte
@@ -2,10 +2,10 @@
   import { TableBodyCell } from 'flowbite-svelte';
 
   import type { TaskResults } from '#lib/types/task.js';
-  import type { WorkBookTasksBase } from '$features/workbooks/types/workbook';
+  import type { WorkBookTasksBase } from '#features/workbooks/types/workbook.js';
 
   import ThermometerProgressBar from '#lib/components/ThermometerProgressBar.svelte';
-  import AcceptedCounter from '$features/workbooks/components/list/AcceptedCounter.svelte';
+  import AcceptedCounter from '#features/workbooks/components/list/AcceptedCounter.svelte';
 
   interface Props {
     workBookTasks: WorkBookTasksBase;
diff --git a/src/features/workbooks/components/shared/WorkBookForm.svelte b/src/features/workbooks/components/shared/WorkBookForm.svelte
index 058ccc906..e0639a2d8 100644
--- a/src/features/workbooks/components/shared/WorkBookForm.svelte
+++ b/src/features/workbooks/components/shared/WorkBookForm.svelte
@@ -2,8 +2,8 @@
   import { Breadcrumb, BreadcrumbItem } from 'flowbite-svelte';
 
   import HeadingOne from '#lib/components/HeadingOne.svelte';
-  import WorkBookInputFields from '$features/workbooks/components/shared/WorkBookInputFields.svelte';
-  import WorkBookTasksTable from '$features/workbooks/components/detail/WorkBookTasksTable.svelte';
+  import WorkBookInputFields from '#features/workbooks/components/shared/WorkBookInputFields.svelte';
+  import WorkBookTasksTable from '#features/workbooks/components/detail/WorkBookTasksTable.svelte';
   import TaskSearchBox from '#lib/components/TaskSearchBox.svelte';
   import InputFieldWrapper from '#lib/components/InputFieldWrapper.svelte';
   import SubmissionButton from '#lib/components/SubmissionButton.svelte';
@@ -16,7 +16,7 @@
     WorkBookTasksCreate,
     WorkBookTaskEdit,
     WorkBookTasksEdit,
-  } from '$features/workbooks/types/workbook';
+  } from '#features/workbooks/types/workbook.js';
 
   interface Props {
     pageTitle: string;
diff --git a/src/features/workbooks/components/shared/WorkBookInputFields.svelte b/src/features/workbooks/components/shared/WorkBookInputFields.svelte
index 416a4dd89..baf085e98 100644
--- a/src/features/workbooks/components/shared/WorkBookInputFields.svelte
+++ b/src/features/workbooks/components/shared/WorkBookInputFields.svelte
@@ -2,7 +2,7 @@
   import MessageHelperWrapper from '#lib/components/MessageHelperWrapper.svelte';
   import InputFieldWrapper from '#lib/components/InputFieldWrapper.svelte';
   import SelectWrapper from '#lib/components/SelectWrapper.svelte';
-  import { WorkBookType } from '$features/workbooks/types/workbook';
+  import { WorkBookType } from '#features/workbooks/types/workbook.js';
 
   interface Props {
     // FIXME: 引数がとても多いので、コンポーネントに渡す引数を減らす方法を調べて実装。
diff --git a/src/features/workbooks/fixtures/solution_category_map.ts b/src/features/workbooks/fixtures/solution_category_map.ts
index c6d2d1b78..e3e6f1941 100644
--- a/src/features/workbooks/fixtures/solution_category_map.ts
+++ b/src/features/workbooks/fixtures/solution_category_map.ts
@@ -1,4 +1,4 @@
-import { SolutionCategory } from '$features/workbooks/types/workbook_placement';
+import { SolutionCategory } from '#features/workbooks/types/workbook_placement.js';
 
 /**
  * Maps urlSlug → SolutionCategory for seeding.
diff --git a/src/features/workbooks/fixtures/workbook_placements.ts b/src/features/workbooks/fixtures/workbook_placements.ts
index 0079c218d..433727459 100644
--- a/src/features/workbooks/fixtures/workbook_placements.ts
+++ b/src/features/workbooks/fixtures/workbook_placements.ts
@@ -1,12 +1,12 @@
 import { TaskGrade, type Task } from '#lib/types/task.js';
-import { WorkBookType } from '$features/workbooks/types/workbook';
+import { WorkBookType } from '#features/workbooks/types/workbook.js';
 import {
   SolutionCategory,
   type WorkBookPlacements,
   type WorkbooksWithPlacement,
   type WorkBooksWithTasks,
   type UnplacedCurriculumRows,
-} from '$features/workbooks/types/workbook_placement';
+} from '#features/workbooks/types/workbook_placement.js';
 
 // ---------------------------------------------------------------------------
 // Placement records (WorkBookPlacement shape)
diff --git a/src/features/workbooks/fixtures/workbooks.ts b/src/features/workbooks/fixtures/workbooks.ts
index 4a57a4102..3dfda7b7c 100644
--- a/src/features/workbooks/fixtures/workbooks.ts
+++ b/src/features/workbooks/fixtures/workbooks.ts
@@ -1,4 +1,4 @@
-import { WorkBookType, type WorkBook } from '$features/workbooks/types/workbook';
+import { WorkBookType, type WorkBook } from '#features/workbooks/types/workbook.js';
 
 function createWorkBookBase(overrides: Partial<WorkBook> = {}): WorkBook {
   return {
diff --git a/src/features/workbooks/server/cache.ts b/src/features/workbooks/server/cache.ts
index 042b9ca60..842f1368d 100644
--- a/src/features/workbooks/server/cache.ts
+++ b/src/features/workbooks/server/cache.ts
@@ -1,5 +1,5 @@
 import { Cache, DEFAULT_CACHE_TTL } from '#lib/clients/cache.js';
-import type { WorkbooksWithAuthors } from '$features/workbooks/types/workbook';
+import type { WorkbooksWithAuthors } from '#features/workbooks/types/workbook.js';
 
 const BY_USER_KEY = 'workbooks_by_user';
 
diff --git a/src/features/workbooks/services/workbook_placements/crud.test.ts b/src/features/workbooks/services/workbook_placements/crud.test.ts
index bfe252253..78376e825 100644
--- a/src/features/workbooks/services/workbook_placements/crud.test.ts
+++ b/src/features/workbooks/services/workbook_placements/crud.test.ts
@@ -1,11 +1,11 @@
 import { describe, test, expect, vi } from 'vitest';
 
 import { TaskGrade } from '#lib/types/task.js';
-import { WorkBookType } from '$features/workbooks/types/workbook';
+import { WorkBookType } from '#features/workbooks/types/workbook.js';
 import {
   SolutionCategory,
   type WorkBookPlacements,
-} from '$features/workbooks/types/workbook_placement';
+} from '#features/workbooks/types/workbook_placement.js';
 
 import {
   getWorkbooksWithPlacements,
@@ -24,7 +24,7 @@ import {
   solutionPlacementRow,
   unplacedCurriculumRows,
   unplacedSolutionWorkbooks,
-} from '$features/workbooks/fixtures/workbook_placements';
+} from '#features/workbooks/fixtures/workbook_placements.js';
 
 vi.mock('#lib/server/database.js', () => ({
   default: {
diff --git a/src/features/workbooks/services/workbook_placements/crud.ts b/src/features/workbooks/services/workbook_placements/crud.ts
index 48b8a3331..8379341f4 100644
--- a/src/features/workbooks/services/workbook_placements/crud.ts
+++ b/src/features/workbooks/services/workbook_placements/crud.ts
@@ -6,9 +6,9 @@ import {
   type WorkbooksWithPlacement,
   type PlacementInputs,
   type PlacementCreates,
-} from '$features/workbooks/types/workbook_placement';
+} from '#features/workbooks/types/workbook_placement.js';
 
-import { WorkBookType } from '$features/workbooks/types/workbook';
+import { WorkBookType } from '#features/workbooks/types/workbook.js';
 
 import {
   buildTaskMapFromCurriculumRows,
diff --git a/src/features/workbooks/services/workbook_placements/initializers.test.ts b/src/features/workbooks/services/workbook_placements/initializers.test.ts
index 6a78a2656..acbecda73 100644
--- a/src/features/workbooks/services/workbook_placements/initializers.test.ts
+++ b/src/features/workbooks/services/workbook_placements/initializers.test.ts
@@ -4,7 +4,7 @@ import { TaskGrade } from '#lib/types/task.js';
 import {
   SolutionCategory,
   type UnplacedCurriculumRows,
-} from '$features/workbooks/types/workbook_placement';
+} from '#features/workbooks/types/workbook_placement.js';
 
 import {
   buildTaskMapFromCurriculumRows,
@@ -18,7 +18,7 @@ import {
 import {
   tasksMapByIds,
   curriculumWorkbooksForInit,
-} from '$features/workbooks/fixtures/workbook_placements';
+} from '#features/workbooks/fixtures/workbook_placements.js';
 
 describe('buildTaskMapFromCurriculumRows', () => {
   test('builds a task_id → Task map from nested workbook rows', () => {
diff --git a/src/features/workbooks/services/workbook_placements/initializers.ts b/src/features/workbooks/services/workbook_placements/initializers.ts
index 1167287a8..a149e9650 100644
--- a/src/features/workbooks/services/workbook_placements/initializers.ts
+++ b/src/features/workbooks/services/workbook_placements/initializers.ts
@@ -4,9 +4,9 @@ import {
   type WorkBooksWithTasks,
   type PlacementCreates,
   type UnplacedCurriculumRows,
-} from '$features/workbooks/types/workbook_placement';
+} from '#features/workbooks/types/workbook_placement.js';
 
-import { calcWorkBookGradeModes } from '$features/workbooks/utils/workbooks';
+import { calcWorkBookGradeModes } from '#features/workbooks/utils/workbooks.js';
 
 // --- Curriculum-specific initialization ---
 
diff --git a/src/features/workbooks/services/workbook_tasks.test.ts b/src/features/workbooks/services/workbook_tasks.test.ts
index 96ddbec64..d8efc9a47 100644
--- a/src/features/workbooks/services/workbook_tasks.test.ts
+++ b/src/features/workbooks/services/workbook_tasks.test.ts
@@ -4,12 +4,12 @@ import {
   WorkBookType,
   type WorkBook,
   type WorkBookTasksBase,
-} from '$features/workbooks/types/workbook';
+} from '#features/workbooks/types/workbook.js';
 
 import {
   getWorkBookTasks,
   validateRequiredFields,
-} from '$features/workbooks/services/workbook_tasks';
+} from '#features/workbooks/services/workbook_tasks.js';
 
 function createWorkBook(overrides: Partial<Omit<WorkBook, 'id'>> = {}): Omit<WorkBook, 'id'> {
   return {
diff --git a/src/features/workbooks/services/workbook_tasks.ts b/src/features/workbooks/services/workbook_tasks.ts
index c3444d87a..e21381ea1 100644
--- a/src/features/workbooks/services/workbook_tasks.ts
+++ b/src/features/workbooks/services/workbook_tasks.ts
@@ -1,4 +1,4 @@
-import type { WorkBook, WorkBookTasksBase } from '$features/workbooks/types/workbook';
+import type { WorkBook, WorkBookTasksBase } from '#features/workbooks/types/workbook.js';
 
 /** Extracts the task list (taskId, priority, comment) from a workbook. */
 export function getWorkBookTasks(workBook: Omit<WorkBook, 'id'>): WorkBookTasksBase {
diff --git a/src/features/workbooks/services/workbooks.test.ts b/src/features/workbooks/services/workbooks.test.ts
index e545b4a13..2f957ccaa 100644
--- a/src/features/workbooks/services/workbooks.test.ts
+++ b/src/features/workbooks/services/workbooks.test.ts
@@ -13,8 +13,8 @@ import {
   getSolutionCategoryMapByWorkbookId,
 } from './workbooks';
 import { TaskGrade } from '#lib/types/task.js';
-import { WorkBookType, type WorkBook } from '$features/workbooks/types/workbook';
-import { SolutionCategory } from '$features/workbooks/types/workbook_placement';
+import { WorkBookType, type WorkBook } from '#features/workbooks/types/workbook.js';
+import { SolutionCategory } from '#features/workbooks/types/workbook_placement.js';
 
 vi.mock('#lib/server/database.js', () => ({
   default: {
@@ -40,7 +40,7 @@ vi.mock('#lib/services/users.js', () => ({
   getUserById: vi.fn(),
 }));
 
-vi.mock('$features/workbooks/server/cache', () => ({
+vi.mock('#features/workbooks/server/cache.js', () => ({
   getCachedWorkbooksByPlacement: (_key: string, fetchFn: () => Promise<unknown>) => fetchFn(),
   getCachedWorkbooksByUser: (fetchFn: () => Promise<unknown>) => fetchFn(),
   invalidateWorkbookCaches: vi.fn(),
diff --git a/src/features/workbooks/services/workbooks.ts b/src/features/workbooks/services/workbooks.ts
index 8e6841ab5..b6a77476f 100644
--- a/src/features/workbooks/services/workbooks.ts
+++ b/src/features/workbooks/services/workbooks.ts
@@ -6,30 +6,30 @@ import type {
   WorkbooksWithAuthors,
   WorkBookTasksBase,
   WorkBookType,
-} from '$features/workbooks/types/workbook';
-import { WorkBookType as WorkBookTypeConst } from '$features/workbooks/types/workbook';
+} from '#features/workbooks/types/workbook.js';
+import { WorkBookType as WorkBookTypeConst } from '#features/workbooks/types/workbook.js';
 import {
   type PlacementQuery,
   SolutionCategory,
   type SolutionCategories,
   ALL_SOLUTION_CATEGORIES,
-} from '$features/workbooks/types/workbook_placement';
+} from '#features/workbooks/types/workbook_placement.js';
 
 import {
   getWorkBookTasks,
   validateRequiredFields,
-} from '$features/workbooks/services/workbook_tasks';
+} from '#features/workbooks/services/workbook_tasks.js';
 import * as userCrud from '#lib/services/users.js';
 
 import {
   getCachedWorkbooksByPlacement,
   getCachedWorkbooksByUser,
   invalidateWorkbookCaches,
-} from '$features/workbooks/server/cache';
+} from '#features/workbooks/server/cache.js';
 
 import { sanitizeUrl } from '#lib/utils/url.js';
-import { parseWorkBookId, parseWorkBookUrlSlug } from '$features/workbooks/utils/workbook';
-import { buildPlacementKey } from '$features/workbooks/utils/workbooks';
+import { parseWorkBookId, parseWorkBookUrlSlug } from '#features/workbooks/utils/workbook.js';
+import { buildPlacementKey } from '#features/workbooks/utils/workbooks.js';
 
 export async function getWorkBooks(): Promise<WorkBooks> {
   const workbooks = await db.workBook.findMany({
diff --git a/src/features/workbooks/stores/replenishment_workbook.test.ts b/src/features/workbooks/stores/replenishment_workbook.test.ts
index cbba5d863..07ba8c782 100644
--- a/src/features/workbooks/stores/replenishment_workbook.test.ts
+++ b/src/features/workbooks/stores/replenishment_workbook.test.ts
@@ -5,7 +5,7 @@ import { describe, test, expect, vi, beforeEach, afterEach } from 'vitest';
 import {
   replenishmentWorkBooksStore,
   ReplenishmentWorkBooksStore,
-} from '$features/workbooks/stores/replenishment_workbook.svelte';
+} from '#features/workbooks/stores/replenishment_workbook.svelte.js';
 
 // WHY: a single dynamic mock is the only way to toggle `browser` per describe. Every vi.mock is
 // hoisted and the last registration for a module wins, so a second vi.mock of `$app/environment`
diff --git a/src/features/workbooks/types/workbook_placement.ts b/src/features/workbooks/types/workbook_placement.ts
index 45e8cf7a5..f437ed52b 100644
--- a/src/features/workbooks/types/workbook_placement.ts
+++ b/src/features/workbooks/types/workbook_placement.ts
@@ -1,7 +1,7 @@
 import type { SolutionCategory as SolutionCategoryOrigin } from '@prisma/client';
 import type { TaskGrade } from '#lib/types/task.js';
-import type { WorkBookTaskBase } from '$features/workbooks/types/workbook';
-import { WorkBookType as WorkBookTypeConst } from '$features/workbooks/types/workbook';
+import type { WorkBookTaskBase } from '#features/workbooks/types/workbook.js';
+import { WorkBookType as WorkBookTypeConst } from '#features/workbooks/types/workbook.js';
 
 // Categories for solution placement.
 export const SolutionCategory: { [key in SolutionCategoryOrigin]: key } = {
diff --git a/src/features/workbooks/utils/solution_category_group.test.ts b/src/features/workbooks/utils/solution_category_group.test.ts
index 4b4e66655..f6884f7b4 100644
--- a/src/features/workbooks/utils/solution_category_group.test.ts
+++ b/src/features/workbooks/utils/solution_category_group.test.ts
@@ -1,7 +1,7 @@
 import { describe, test, expect } from 'vitest';
 import { Roles } from '#lib/types/user.js';
-import { SolutionCategory } from '$features/workbooks/types/workbook_placement';
-import type { WorkbooksList } from '$features/workbooks/types/workbook';
+import { SolutionCategory } from '#features/workbooks/types/workbook_placement.js';
+import type { WorkbooksList } from '#features/workbooks/types/workbook.js';
 import { groupBySolutionCategory, filterGroupsByRole } from './solution_category_group';
 
 // groupBySolutionCategory references only the workbook id, so minimal fixtures are sufficient.
diff --git a/src/features/workbooks/utils/solution_category_group.ts b/src/features/workbooks/utils/solution_category_group.ts
index bb7c27082..3a40d1b05 100644
--- a/src/features/workbooks/utils/solution_category_group.ts
+++ b/src/features/workbooks/utils/solution_category_group.ts
@@ -1,6 +1,6 @@
 import { Roles } from '#lib/types/user.js';
-import type { WorkbooksList } from '$features/workbooks/types/workbook';
-import { SolutionCategory } from '$features/workbooks/types/workbook_placement';
+import type { WorkbooksList } from '#features/workbooks/types/workbook.js';
+import { SolutionCategory } from '#features/workbooks/types/workbook_placement.js';
 
 export type WorkbookGroup = {
   category: SolutionCategory;
diff --git a/src/features/workbooks/utils/workbook.test.ts b/src/features/workbooks/utils/workbook.test.ts
index 45998940a..83f379d54 100644
--- a/src/features/workbooks/utils/workbook.test.ts
+++ b/src/features/workbooks/utils/workbook.test.ts
@@ -1,5 +1,5 @@
 import { expect, test } from 'vitest';
-import { parseWorkBookId, parseWorkBookUrlSlug } from '$features/workbooks/utils/workbook';
+import { parseWorkBookId, parseWorkBookUrlSlug } from '#features/workbooks/utils/workbook.js';
 
 type TestCase = {
   slug: string;
diff --git a/src/features/workbooks/utils/workbook_tasks.test.ts b/src/features/workbooks/utils/workbook_tasks.test.ts
index c5f5b85dd..db823f08b 100644
--- a/src/features/workbooks/utils/workbook_tasks.test.ts
+++ b/src/features/workbooks/utils/workbook_tasks.test.ts
@@ -6,14 +6,14 @@ import type {
   WorkBookTasksBase,
   WorkBookTasksCreate,
   WorkBookTasksEdit,
-} from '$features/workbooks/types/workbook';
+} from '#features/workbooks/types/workbook.js';
 
 import {
   generateWorkBookTaskOrders,
   addTaskToWorkBook,
   updateWorkBookTasks,
   updateWorkBookTaskForTable,
-} from '$features/workbooks/utils/workbook_tasks';
+} from '#features/workbooks/utils/workbook_tasks.js';
 
 type TestCaseForWorkBookTaskOrders = {
   workBookTaskCount: number;
diff --git a/src/features/workbooks/utils/workbook_tasks.ts b/src/features/workbooks/utils/workbook_tasks.ts
index f11aa2425..111b0bc83 100644
--- a/src/features/workbooks/utils/workbook_tasks.ts
+++ b/src/features/workbooks/utils/workbook_tasks.ts
@@ -6,7 +6,7 @@ import type {
   WorkBookTasksCreate,
   WorkBookTaskEdit,
   WorkBookTasksEdit,
-} from '$features/workbooks/types/workbook';
+} from '#features/workbooks/types/workbook.js';
 
 // Note: 0-indexed for both display and internal use
 export function generateWorkBookTaskOrders(workBookTaskCount: number) {
diff --git a/src/features/workbooks/utils/workbook_url_params.test.ts b/src/features/workbooks/utils/workbook_url_params.test.ts
index a001d8e43..b3b39475e 100644
--- a/src/features/workbooks/utils/workbook_url_params.test.ts
+++ b/src/features/workbooks/utils/workbook_url_params.test.ts
@@ -1,7 +1,7 @@
 import { describe, test, expect } from 'vitest';
 import { TaskGrade } from '#lib/types/task.js';
-import { SolutionCategory } from '$features/workbooks/types/workbook_placement';
-import { WorkBookTab } from '$features/workbooks/types/workbook';
+import { SolutionCategory } from '#features/workbooks/types/workbook_placement.js';
+import { WorkBookTab } from '#features/workbooks/types/workbook.js';
 import {
   parseWorkBookTab,
   parseWorkBookGrade,
diff --git a/src/features/workbooks/utils/workbook_url_params.ts b/src/features/workbooks/utils/workbook_url_params.ts
index b33c20f33..7a04ddcf1 100644
--- a/src/features/workbooks/utils/workbook_url_params.ts
+++ b/src/features/workbooks/utils/workbook_url_params.ts
@@ -1,10 +1,10 @@
 import { TaskGrade } from '#lib/types/task.js';
-import { WorkBookTab, DEFAULT_WORKBOOK_TAB } from '$features/workbooks/types/workbook';
+import { WorkBookTab, DEFAULT_WORKBOOK_TAB } from '#features/workbooks/types/workbook.js';
 import {
   SolutionCategory,
   ALL_SOLUTION_CATEGORIES,
   type SelectedSolutionCategory,
-} from '$features/workbooks/types/workbook_placement';
+} from '#features/workbooks/types/workbook_placement.js';
 
 const DEFAULT_CURRICULUM_GRADE = TaskGrade.Q10;
 const EXISTING_TABS = new Set<string>(Object.values(WorkBookTab));
diff --git a/src/features/workbooks/utils/workbooks.test.ts b/src/features/workbooks/utils/workbooks.test.ts
index 40b5d3e75..7c58fb84b 100644
--- a/src/features/workbooks/utils/workbooks.test.ts
+++ b/src/features/workbooks/utils/workbooks.test.ts
@@ -2,9 +2,9 @@ import { describe, expect, test } from 'vitest';
 
 import { Roles } from '#lib/types/user.js';
 import { TaskGrade, type Task, type TaskResult } from '#lib/types/task.js';
-import { type WorkbookList, WorkBookType } from '$features/workbooks/types/workbook';
-import { SolutionCategory } from '$features/workbooks/types/workbook_placement';
-import type { PlacementQuery } from '$features/workbooks/types/workbook_placement';
+import { type WorkbookList, WorkBookType } from '#features/workbooks/types/workbook.js';
+import { SolutionCategory } from '#features/workbooks/types/workbook_placement.js';
+import type { PlacementQuery } from '#features/workbooks/types/workbook_placement.js';
 
 import {
   buildPlacementKey,
@@ -18,7 +18,7 @@ import {
   getTaskResult,
   countReadableWorkbooks,
   partitionWorkbooksAsMainAndReplenished,
-} from '$features/workbooks/utils/workbooks';
+} from '#features/workbooks/utils/workbooks.js';
 
 function createTask(taskId: string, grade: TaskGrade): Task {
   return {
diff --git a/src/features/workbooks/utils/workbooks.ts b/src/features/workbooks/utils/workbooks.ts
index 97b017098..e5a32e0bb 100644
--- a/src/features/workbooks/utils/workbooks.ts
+++ b/src/features/workbooks/utils/workbooks.ts
@@ -12,9 +12,9 @@ import type {
   WorkbooksList,
   WorkBookTaskBase,
   WorkBookType,
-} from '$features/workbooks/types/workbook';
-import { WorkBookType as WorkBookTypeConst } from '$features/workbooks/types/workbook';
-import type { PlacementQuery } from '$features/workbooks/types/workbook_placement';
+} from '#features/workbooks/types/workbook.js';
+import { WorkBookType as WorkBookTypeConst } from '#features/workbooks/types/workbook.js';
+import type { PlacementQuery } from '#features/workbooks/types/workbook_placement.js';
 
 import { isAdmin, canRead } from '#lib/utils/authorship.js';
 import { calcGradeMode } from '#lib/utils/task.js';
diff --git a/src/features/workbooks/zod/schema.test.ts b/src/features/workbooks/zod/schema.test.ts
index c4bc84204..5181c6636 100644
--- a/src/features/workbooks/zod/schema.test.ts
+++ b/src/features/workbooks/zod/schema.test.ts
@@ -4,10 +4,10 @@ import { superValidate } from 'sveltekit-superforms/server';
 import { zod4 } from 'sveltekit-superforms/adapters';
 
 import { TaskGrade } from '#lib/types/task.js';
-import { WorkBookType, type WorkBookTasks } from '$features/workbooks/types/workbook';
-import { SolutionCategory } from '$features/workbooks/types/workbook_placement';
+import { WorkBookType, type WorkBookTasks } from '#features/workbooks/types/workbook.js';
+import { SolutionCategory } from '#features/workbooks/types/workbook_placement.js';
 
-import { workBookSchema, workBookPlacementSchema } from '$features/workbooks/zod/schema';
+import { workBookSchema, workBookPlacementSchema } from '#features/workbooks/zod/schema.js';
 
 type WorkBook = {
   authorId: string;
diff --git a/src/features/workbooks/zod/schema.ts b/src/features/workbooks/zod/schema.ts
index 021c41af3..e5781cec1 100644
--- a/src/features/workbooks/zod/schema.ts
+++ b/src/features/workbooks/zod/schema.ts
@@ -5,8 +5,8 @@
 import { z } from 'zod';
 
 import { TaskGrade } from '#lib/types/task.js';
-import { WorkBookType } from '$features/workbooks/types/workbook';
-import { SolutionCategory } from '$features/workbooks/types/workbook_placement';
+import { WorkBookType } from '#features/workbooks/types/workbook.js';
+import { SolutionCategory } from '#features/workbooks/types/workbook_placement.js';
 
 import { isValidUrl, isValidUrlSlug } from '#lib/utils/url.js';
 
diff --git a/src/hooks.server.ts b/src/hooks.server.ts
index 361b4acbf..03e158386 100644
--- a/src/hooks.server.ts
+++ b/src/hooks.server.ts
@@ -3,7 +3,7 @@
 // https://tech-blog.rakus.co.jp/entry/20230209/sveltekit
 import type { Handle } from '@sveltejs/kit';
 
-import { createAuthRequest } from '$features/auth/server/auth';
+import { createAuthRequest } from '#features/auth/server/auth.js';
 
 import * as userService from '#lib/services/users.js';
 
diff --git a/src/lib/components/SubmissionStatus/UpdatingDropdown.svelte b/src/lib/components/SubmissionStatus/UpdatingDropdown.svelte
index 30f6804be..6e164f186 100644
--- a/src/lib/components/SubmissionStatus/UpdatingDropdown.svelte
+++ b/src/lib/components/SubmissionStatus/UpdatingDropdown.svelte
@@ -33,8 +33,8 @@
   import { submission_statuses } from '#lib/services/submission_status.js';
   import { errorMessageStore } from '#lib/stores/error_message.js';
 
-  import { buildLoginPath } from '$features/auth/utils/login';
-  import { buildSignupPath } from '$features/auth/utils/signup';
+  import { buildLoginPath } from '#features/auth/utils/login.js';
+  import { buildSignupPath } from '#features/auth/utils/signup.js';
 
   interface Props {
     taskResult: TaskResult;
diff --git a/src/lib/components/TaskSearchBox.svelte b/src/lib/components/TaskSearchBox.svelte
index fc5d3d875..3d566dc04 100644
--- a/src/lib/components/TaskSearchBox.svelte
+++ b/src/lib/components/TaskSearchBox.svelte
@@ -12,14 +12,14 @@
     WorkBookTasksBase,
     WorkBookTasksCreate,
     WorkBookTasksEdit,
-  } from '$features/workbooks/types/workbook';
+  } from '#features/workbooks/types/workbook.js';
 
   import { getTaskUrl } from '#lib/utils/task.js';
   import {
     generateWorkBookTaskOrders,
     addTaskToWorkBook,
     PENDING,
-  } from '$features/workbooks/utils/workbook_tasks';
+  } from '#features/workbooks/utils/workbook_tasks.js';
 
   interface Props {
     tasks?: Tasks;
diff --git a/src/lib/components/ThermometerProgressBar.svelte b/src/lib/components/ThermometerProgressBar.svelte
index 17c4be347..9e4371be3 100644
--- a/src/lib/components/ThermometerProgressBar.svelte
+++ b/src/lib/components/ThermometerProgressBar.svelte
@@ -3,7 +3,7 @@
 
   import type { TaskResult, TaskResults } from '#lib/types/task.js';
   import type { SubmissionRatios, SubmissionCounts } from '#lib/types/submission.js';
-  import type { WorkBookTaskBase } from '$features/workbooks/types/workbook';
+  import type { WorkBookTaskBase } from '#features/workbooks/types/workbook.js';
 
   import { submission_statuses } from '#lib/services/submission_status.js';
 
diff --git a/src/lib/components/Trophies/CompletedTasks.svelte b/src/lib/components/Trophies/CompletedTasks.svelte
index fd4fc57bf..66485731a 100644
--- a/src/lib/components/Trophies/CompletedTasks.svelte
+++ b/src/lib/components/Trophies/CompletedTasks.svelte
@@ -2,7 +2,7 @@
   import { Img } from 'flowbite-svelte';
 
   import type { TaskResults } from '#lib/types/task.js';
-  import type { WorkBookTaskBase } from '$features/workbooks/types/workbook';
+  import type { WorkBookTaskBase } from '#features/workbooks/types/workbook.js';
 
   import { areAllTasksAccepted } from '#lib/utils/task.js';
 
diff --git a/src/lib/services/task_results.ts b/src/lib/services/task_results.ts
index 6737f730d..a8f7dc62c 100644
--- a/src/lib/services/task_results.ts
+++ b/src/lib/services/task_results.ts
@@ -24,7 +24,7 @@ import type { User } from '@prisma/client';
 import type { TaskResult, TaskResults, Task, Tasks } from '#lib/types/task.js';
 import type { TaskAnswer } from '#lib/types/answer.js';
 import type { FloatingMessages } from '#lib/types/floating_message.js';
-import type { WorkBookTasksBase } from '$features/workbooks/types/workbook';
+import type { WorkBookTasksBase } from '#features/workbooks/types/workbook.js';
 
 import { NOT_FOUND } from '#lib/constants/http-response-status-codes.js';
 
diff --git a/src/lib/services/tasks.ts b/src/lib/services/tasks.ts
index 1cea000f9..de5698caf 100644
--- a/src/lib/services/tasks.ts
+++ b/src/lib/services/tasks.ts
@@ -16,7 +16,7 @@ import {
   getCachedMergedTasksMap,
   invalidateTaskCaches,
 } from '#lib/server/tasks/cache.js';
-import { invalidateVoteCaches } from '$features/votes/server/cache';
+import { invalidateVoteCaches } from '#features/votes/server/cache.js';
 
 import { classifyContest } from '#lib/contests/index.js';
 import { createContestTaskPairKey } from '#lib/utils/contest_task_pair.js';
diff --git a/src/lib/utils/task.ts b/src/lib/utils/task.ts
index 5d768b311..f5ac762f0 100644
--- a/src/lib/utils/task.ts
+++ b/src/lib/utils/task.ts
@@ -2,7 +2,7 @@ import { ContestType } from '#lib/contests/types/contest.js';
 import { type TaskResult, type TaskResults, TaskGrade, type TaskGrades } from '#lib/types/task.js';
 import type { UrlGenerator, UrlGenerators } from '#lib/types/url.js';
 
-import { type WorkBookTaskBase } from '$features/workbooks/types/workbook';
+import { type WorkBookTaskBase } from '#features/workbooks/types/workbook.js';
 
 import { ATCODER_BASE_CONTEST_URL, AOJ_TASKS_URL } from '#lib/constants/urls.js';
 import {
diff --git a/src/routes/(admin)/account_transfer/+page.server.ts b/src/routes/(admin)/account_transfer/+page.server.ts
index 7836e0567..2316e48c2 100644
--- a/src/routes/(admin)/account_transfer/+page.server.ts
+++ b/src/routes/(admin)/account_transfer/+page.server.ts
@@ -9,7 +9,7 @@ import * as taskResultService from '#lib/services/task_results.js';
 import { accountTransferSchema } from '#lib/zod/schema.js';
 import type { FloatingMessage } from '#lib/types/floating_message.js';
 
-import { validateAdminAccess } from '$features/auth/services/admin_access';
+import { validateAdminAccess } from '#features/auth/services/admin_access.js';
 
 let accountTransferMessages: FloatingMessage[] = [];
 
diff --git a/src/routes/(admin)/tags/+page.server.ts b/src/routes/(admin)/tags/+page.server.ts
index e7b31c257..2184920d3 100644
--- a/src/routes/(admin)/tags/+page.server.ts
+++ b/src/routes/(admin)/tags/+page.server.ts
@@ -4,7 +4,7 @@ import type { Tag } from '#lib/types/tag.js';
 
 import * as tagService from '#lib/services/tags.js';
 
-import { validateAdminAccess } from '$features/auth/services/admin_access';
+import { validateAdminAccess } from '#features/auth/services/admin_access.js';
 
 export async function load({ locals, url }) {
   await validateAdminAccess(locals, url);
diff --git a/src/routes/(admin)/tags/[tag_id]/+page.server.ts b/src/routes/(admin)/tags/[tag_id]/+page.server.ts
index 249af0350..389a9d0d1 100644
--- a/src/routes/(admin)/tags/[tag_id]/+page.server.ts
+++ b/src/routes/(admin)/tags/[tag_id]/+page.server.ts
@@ -2,7 +2,7 @@ import { error } from '@sveltejs/kit';
 
 import type { Tasks } from '#lib/types/task.js';
 
-import { validateAdminAccess } from '$features/auth/services/admin_access';
+import { validateAdminAccess } from '#features/auth/services/admin_access.js';
 import * as tagService from '#lib/services/tags.js';
 import * as taskTagService from '#lib/services/task_tags.js';
 
diff --git a/src/routes/(admin)/tasks/+page.server.ts b/src/routes/(admin)/tasks/+page.server.ts
index b56ceea42..e544a4938 100644
--- a/src/routes/(admin)/tasks/+page.server.ts
+++ b/src/routes/(admin)/tasks/+page.server.ts
@@ -4,7 +4,7 @@ import type { Contests, ContestForImport, ContestsForImport } from '#lib/contest
 import { type Task, type Tasks, type TaskForImport, type TasksForImport } from '#lib/types/task.js';
 
 import * as taskService from '#lib/services/tasks.js';
-import { validateAdminAccess } from '$features/auth/services/admin_access';
+import { validateAdminAccess } from '#features/auth/services/admin_access.js';
 
 import { fetchContests, fetchTasks, isContestTaskImportSource } from '#lib/clients/index.js';
 
diff --git a/src/routes/(admin)/tasks/[task_id]/+page.server.ts b/src/routes/(admin)/tasks/[task_id]/+page.server.ts
index 8d3f94b4d..0b1c0ec00 100644
--- a/src/routes/(admin)/tasks/[task_id]/+page.server.ts
+++ b/src/routes/(admin)/tasks/[task_id]/+page.server.ts
@@ -8,7 +8,7 @@ import * as taskService from '#lib/services/tasks.js';
 import * as taskTagsApiService from '#lib/services/tasktagsApiService.js';
 import * as taskTagsService from '#lib/services/task_tags.js';
 
-import { validateAdminAccess } from '$features/auth/services/admin_access';
+import { validateAdminAccess } from '#features/auth/services/admin_access.js';
 
 import { BAD_REQUEST, INTERNAL_SERVER_ERROR } from '#lib/constants/http-response-status-codes.js';
 
diff --git a/src/routes/(admin)/tasks/grade/+page.server.ts b/src/routes/(admin)/tasks/grade/+page.server.ts
index e550326d9..f1a3bac8b 100644
--- a/src/routes/(admin)/tasks/grade/+page.server.ts
+++ b/src/routes/(admin)/tasks/grade/+page.server.ts
@@ -3,8 +3,8 @@ import type { Actions, PageServerLoad } from './$types';
 import { type TaskGrade, TaskGrade as TaskGradeEnum } from '#lib/types/task.js';
 
 import { updateTask } from '#lib/services/tasks.js';
-import { getAllTasksWithVoteInfo } from '$features/votes/services/vote_statistics';
-import { validateAdminAccess } from '$features/auth/services/admin_access';
+import { getAllTasksWithVoteInfo } from '#features/votes/services/vote_statistics.js';
+import { validateAdminAccess } from '#features/auth/services/admin_access.js';
 
 export const load: PageServerLoad = async ({ locals, url }) => {
   await validateAdminAccess(locals, url);
diff --git a/src/routes/(admin)/tasks/grade/_components/TaskGradeTable.svelte b/src/routes/(admin)/tasks/grade/_components/TaskGradeTable.svelte
index 75197c6da..7e2f4b7ab 100644
--- a/src/routes/(admin)/tasks/grade/_components/TaskGradeTable.svelte
+++ b/src/routes/(admin)/tasks/grade/_components/TaskGradeTable.svelte
@@ -14,10 +14,10 @@
   } from 'flowbite-svelte';
 
   import GradeLabel from '#lib/components/GradeLabel.svelte';
-  import RelativeEvaluationBadge from '$features/votes/components/RelativeEvaluationBadge.svelte';
+  import RelativeEvaluationBadge from '#features/votes/components/RelativeEvaluationBadge.svelte';
 
   import { taskGradeValues, TaskGrade } from '#lib/types/task.js';
-  import type { TaskWithVoteInfo } from '$features/votes/services/vote_statistics';
+  import type { TaskWithVoteInfo } from '#features/votes/services/vote_statistics.js';
 
   import { addContestNameToTaskIndex } from '#lib/contests/index.js';
   import {
diff --git a/src/routes/(admin)/tasks/grade/_utils/grade_table_filter.test.ts b/src/routes/(admin)/tasks/grade/_utils/grade_table_filter.test.ts
index 0ac592928..dcb778ef3 100644
--- a/src/routes/(admin)/tasks/grade/_utils/grade_table_filter.test.ts
+++ b/src/routes/(admin)/tasks/grade/_utils/grade_table_filter.test.ts
@@ -1,7 +1,7 @@
 import { describe, test, expect } from 'vitest';
 
 import { TaskGrade } from '#lib/types/task.js';
-import type { TaskWithVoteInfo } from '$features/votes/services/vote_statistics';
+import type { TaskWithVoteInfo } from '#features/votes/services/vote_statistics.js';
 
 import { countPendingTasks, filterGradeTableTasks } from './grade_table_filter';
 
diff --git a/src/routes/(admin)/tasks/grade/_utils/grade_table_filter.ts b/src/routes/(admin)/tasks/grade/_utils/grade_table_filter.ts
index a11e87af4..db452276a 100644
--- a/src/routes/(admin)/tasks/grade/_utils/grade_table_filter.ts
+++ b/src/routes/(admin)/tasks/grade/_utils/grade_table_filter.ts
@@ -1,4 +1,4 @@
-import type { TaskWithVoteInfo } from '$features/votes/services/vote_statistics';
+import type { TaskWithVoteInfo } from '#features/votes/services/vote_statistics.js';
 import { TaskGrade } from '#lib/types/task.js';
 import { filterTasksBySearch } from '#lib/utils/task_filter.js';
 
diff --git a/src/routes/(admin)/workbooks/order/+page.server.ts b/src/routes/(admin)/workbooks/order/+page.server.ts
index a9a0c0190..eb289d8c8 100644
--- a/src/routes/(admin)/workbooks/order/+page.server.ts
+++ b/src/routes/(admin)/workbooks/order/+page.server.ts
@@ -3,9 +3,9 @@ import { type Actions } from '@sveltejs/kit';
 import {
   getWorkbooksWithPlacements,
   createInitialPlacements,
-} from '$features/workbooks/services/workbook_placements/crud';
+} from '#features/workbooks/services/workbook_placements/crud.js';
 
-import { validateAdminAccess } from '$features/auth/services/admin_access';
+import { validateAdminAccess } from '#features/auth/services/admin_access.js';
 
 export async function load({ locals, url }) {
   await validateAdminAccess(locals, url);
diff --git a/src/routes/(admin)/workbooks/order/+server.ts b/src/routes/(admin)/workbooks/order/+server.ts
index 81aeb6415..6b3d87281 100644
--- a/src/routes/(admin)/workbooks/order/+server.ts
+++ b/src/routes/(admin)/workbooks/order/+server.ts
@@ -1,10 +1,10 @@
 import { json, type RequestEvent } from '@sveltejs/kit';
 
-import { validateAndUpdatePlacements } from '$features/workbooks/services/workbook_placements/crud';
+import { validateAndUpdatePlacements } from '#features/workbooks/services/workbook_placements/crud.js';
 
-import { updatePlacementsSchema } from '$features/workbooks/zod/schema';
+import { updatePlacementsSchema } from '#features/workbooks/zod/schema.js';
 
-import { validateAdminAccessForApi } from '$features/auth/services/admin_access';
+import { validateAdminAccessForApi } from '#features/auth/services/admin_access.js';
 
 import { BAD_REQUEST } from '#lib/constants/http-response-status-codes.js';
 
diff --git a/src/routes/(admin)/workbooks/order/_components/KanbanBoard.svelte b/src/routes/(admin)/workbooks/order/_components/KanbanBoard.svelte
index 619c93b9b..829e15e6a 100644
--- a/src/routes/(admin)/workbooks/order/_components/KanbanBoard.svelte
+++ b/src/routes/(admin)/workbooks/order/_components/KanbanBoard.svelte
@@ -13,7 +13,7 @@
   import {
     SolutionCategory,
     type WorkbooksWithPlacement,
-  } from '$features/workbooks/types/workbook_placement';
+  } from '#features/workbooks/types/workbook_placement.js';
   import { TaskGrade } from '#lib/types/task.js';
   import type {
     KanbanColumns,
diff --git a/src/routes/(admin)/workbooks/order/_components/KanbanCard.svelte b/src/routes/(admin)/workbooks/order/_components/KanbanCard.svelte
index 5029cfac4..5d08dec71 100644
--- a/src/routes/(admin)/workbooks/order/_components/KanbanCard.svelte
+++ b/src/routes/(admin)/workbooks/order/_components/KanbanCard.svelte
@@ -3,8 +3,8 @@
 
   import type { Card, SortableProps } from '../_types/kanban';
 
-  import PublicationStatusLabel from '$features/workbooks/components/shared/PublicationStatusLabel.svelte';
-  import WorkbookLink from '$features/workbooks/components/shared/WorkbookLink.svelte';
+  import PublicationStatusLabel from '#features/workbooks/components/shared/PublicationStatusLabel.svelte';
+  import WorkbookLink from '#features/workbooks/components/shared/WorkbookLink.svelte';
 
   let {
     id: placementId,
diff --git a/src/routes/(admin)/workbooks/order/_components/KanbanTabBar.svelte b/src/routes/(admin)/workbooks/order/_components/KanbanTabBar.svelte
index 879426fb4..9761ea63a 100644
--- a/src/routes/(admin)/workbooks/order/_components/KanbanTabBar.svelte
+++ b/src/routes/(admin)/workbooks/order/_components/KanbanTabBar.svelte
@@ -4,7 +4,10 @@
   import { Tabs } from 'flowbite-svelte';
 
   import { TaskGrade } from '#lib/types/task.js';
-  import { SolutionCategory, SOLUTION_LABELS } from '$features/workbooks/types/workbook_placement';
+  import {
+    SolutionCategory,
+    SOLUTION_LABELS,
+  } from '#features/workbooks/types/workbook_placement.js';
   import type { ActiveTab } from '../_types/kanban';
 
   import TabItemWrapper from '#lib/components/Tabs/TabItemWrapper.svelte';
diff --git a/src/routes/(admin)/workbooks/order/_fixtures/kanban.ts b/src/routes/(admin)/workbooks/order/_fixtures/kanban.ts
index 8ea47b18d..86dbc359b 100644
--- a/src/routes/(admin)/workbooks/order/_fixtures/kanban.ts
+++ b/src/routes/(admin)/workbooks/order/_fixtures/kanban.ts
@@ -1,9 +1,9 @@
 import { TaskGrade } from '#lib/types/task.js';
-import { WorkBookType } from '$features/workbooks/types/workbook';
+import { WorkBookType } from '#features/workbooks/types/workbook.js';
 import {
   SolutionCategory,
   type WorkbooksWithPlacement,
-} from '$features/workbooks/types/workbook_placement';
+} from '#features/workbooks/types/workbook_placement.js';
 import type { KanbanColumns } from '../_types/kanban';
 
 // Workbooks used in buildKanbanItems tests.
diff --git a/src/routes/(admin)/workbooks/order/_types/kanban.ts b/src/routes/(admin)/workbooks/order/_types/kanban.ts
index 3b89ba402..77f3ae7a4 100644
--- a/src/routes/(admin)/workbooks/order/_types/kanban.ts
+++ b/src/routes/(admin)/workbooks/order/_types/kanban.ts
@@ -1,7 +1,7 @@
 import type { DragDropManager, Draggable, Droppable } from '@dnd-kit/dom';
 import type { DragDropEventMap } from '@dnd-kit/abstract';
 
-import type { WorkBookTab } from '$features/workbooks/types/workbook';
+import type { WorkBookTab } from '#features/workbooks/types/workbook.js';
 
 export type DragOverEventArg = DragDropEventMap<Draggable, Droppable, DragDropManager>['dragover'];
 export type DragEndEventArg = DragDropEventMap<Draggable, Droppable, DragDropManager>['dragend'];
diff --git a/src/routes/(admin)/workbooks/order/_utils/kanban.test.ts b/src/routes/(admin)/workbooks/order/_utils/kanban.test.ts
index 4321bf731..260e77ae4 100644
--- a/src/routes/(admin)/workbooks/order/_utils/kanban.test.ts
+++ b/src/routes/(admin)/workbooks/order/_utils/kanban.test.ts
@@ -1,6 +1,6 @@
 import { describe, test, expect } from 'vitest';
 
-import { SolutionCategory } from '$features/workbooks/types/workbook_placement';
+import { SolutionCategory } from '#features/workbooks/types/workbook_placement.js';
 import { TaskGrade } from '#lib/types/task.js';
 
 import { workbooks, solutionColumnsBefore, solutionColumnsGraphSwapped } from '../_fixtures/kanban';
diff --git a/src/routes/(admin)/workbooks/order/_utils/kanban.ts b/src/routes/(admin)/workbooks/order/_utils/kanban.ts
index 4d3a11be9..949095289 100644
--- a/src/routes/(admin)/workbooks/order/_utils/kanban.ts
+++ b/src/routes/(admin)/workbooks/order/_utils/kanban.ts
@@ -4,7 +4,7 @@ import {
   SOLUTION_LABELS,
   type WorkbooksWithPlacement,
   type WorkbookWithPlacement,
-} from '$features/workbooks/types/workbook_placement';
+} from '#features/workbooks/types/workbook_placement.js';
 import type {
   ActiveTab,
   KanbanColumns,
diff --git a/src/routes/(auth)/login/+page.server.ts b/src/routes/(auth)/login/+page.server.ts
index 05880d92b..bfc257005 100644
--- a/src/routes/(auth)/login/+page.server.ts
+++ b/src/routes/(auth)/login/+page.server.ts
@@ -2,8 +2,8 @@
 // See src/lib/utils/auth_forms.ts for the current form handling approach.
 import { fail, redirect } from '@sveltejs/kit';
 
-import { createSession } from '$features/auth/server/session';
-import { authenticateUser } from '$features/auth/services/credentials';
+import { createSession } from '#features/auth/server/session.js';
+import { authenticateUser } from '#features/auth/services/credentials.js';
 
 import { initializeAuthForm, validateAuthFormWithFallback } from '#lib/utils/auth_forms.js';
 import { isSameOriginRedirect } from '#lib/utils/url.js';
diff --git a/src/routes/(auth)/login/+page.svelte b/src/routes/(auth)/login/+page.svelte
index 7ce85a1f2..918070346 100644
--- a/src/routes/(auth)/login/+page.svelte
+++ b/src/routes/(auth)/login/+page.svelte
@@ -5,7 +5,7 @@
 
   import AuthForm from '#lib/components/AuthForm.svelte';
 
-  import { buildSignupPath } from '$features/auth/utils/signup';
+  import { buildSignupPath } from '#features/auth/utils/signup.js';
 
   import { CREATE_ACCOUNT_LABEL, LOGIN_LABEL } from '#lib/constants/forms.js';
 
diff --git a/src/routes/(auth)/logout/+page.server.ts b/src/routes/(auth)/logout/+page.server.ts
index f3514e8a9..a975c5d03 100644
--- a/src/routes/(auth)/logout/+page.server.ts
+++ b/src/routes/(auth)/logout/+page.server.ts
@@ -1,6 +1,6 @@
 import { fail, redirect } from '@sveltejs/kit';
 
-import { invalidateSession } from '$features/auth/server/session';
+import { invalidateSession } from '#features/auth/server/session.js';
 
 import { SEE_OTHER, UNAUTHORIZED } from '#lib/constants/http-response-status-codes.js';
 import { HOME_PAGE } from '#lib/constants/navbar-links.js';
diff --git a/src/routes/(auth)/signup/+page.server.ts b/src/routes/(auth)/signup/+page.server.ts
index 858991f67..fce3c5456 100644
--- a/src/routes/(auth)/signup/+page.server.ts
+++ b/src/routes/(auth)/signup/+page.server.ts
@@ -2,8 +2,8 @@
 // See src/lib/utils/auth_forms.ts for the current form handling approach.
 import { fail, redirect } from '@sveltejs/kit';
 
-import { createSession } from '$features/auth/server/session';
-import { registerUser } from '$features/auth/services/credentials';
+import { createSession } from '#features/auth/server/session.js';
+import { registerUser } from '#features/auth/services/credentials.js';
 
 import { initializeAuthForm, validateAuthFormWithFallback } from '#lib/utils/auth_forms.js';
 import { isSameOriginRedirect } from '#lib/utils/url.js';
diff --git a/src/routes/problems/+page.server.ts b/src/routes/problems/+page.server.ts
index 676487dc0..6adfef1c0 100644
--- a/src/routes/problems/+page.server.ts
+++ b/src/routes/problems/+page.server.ts
@@ -3,11 +3,11 @@ import { superValidate } from 'sveltekit-superforms';
 import { zod4 } from 'sveltekit-superforms/adapters';
 
 import * as task_crud from '#lib/services/task_results.js';
-import { getVoteGradeStatistics } from '$features/votes/services/vote_statistics';
+import { getVoteGradeStatistics } from '#features/votes/services/vote_statistics.js';
 import type { TaskResults } from '#lib/types/task.js';
 import { updateTaskResult } from '#lib/actions/update_task_result.js';
-import { voteAbsoluteGrade } from '@/features/votes/actions/vote_actions';
-import { voteAbsoluteGradeSchema } from '$features/votes/zod/schema';
+import { voteAbsoluteGrade } from '#features/votes/actions/vote_actions.js';
+import { voteAbsoluteGradeSchema } from '#features/votes/zod/schema.js';
 import { BAD_REQUEST } from '#lib/constants/http-response-status-codes.js';
 
 // 一覧表ページは、ログインしていなくても閲覧できるようにする
diff --git a/src/routes/problems/+page.svelte b/src/routes/problems/+page.svelte
index 4b47b96b6..e3c9e0cb9 100644
--- a/src/routes/problems/+page.svelte
+++ b/src/routes/problems/+page.svelte
@@ -7,7 +7,7 @@
 
   import HeadingOne from '#lib/components/HeadingOne.svelte';
   import ProblemListTabItem from '#lib/components/Tabs/ProblemListTabItem.svelte';
-  import TaskTable from '$features/tasks/components/contest-table/TaskTable.svelte';
+  import TaskTable from '#features/tasks/components/contest-table/TaskTable.svelte';
   import TaskGradeList from '#lib/components/TaskGradeList.svelte';
   import GradeGuidelineTable from '#lib/components/TaskGrades/GradeGuidelineTable.svelte';
 
diff --git a/src/routes/problems/[slug]/+page.server.ts b/src/routes/problems/[slug]/+page.server.ts
index 03324c179..51e71a18b 100644
--- a/src/routes/problems/[slug]/+page.server.ts
+++ b/src/routes/problems/[slug]/+page.server.ts
@@ -2,7 +2,7 @@ import { fail, type Actions, redirect } from '@sveltejs/kit';
 
 import * as crud from '#lib/services/task_results.js';
 import { getButtons } from '#lib/services/submission_status.js';
-import { getLoggedInUser } from '$features/auth/services/session_guards';
+import { getLoggedInUser } from '#features/auth/services/session_guards.js';
 
 import { BAD_REQUEST, TEMPORARY_REDIRECT } from '#lib/constants/http-response-status-codes.js';
 
diff --git a/src/routes/problems/getMedianVote/+server.ts b/src/routes/problems/getMedianVote/+server.ts
index 393a5643d..ab9f9acee 100644
--- a/src/routes/problems/getMedianVote/+server.ts
+++ b/src/routes/problems/getMedianVote/+server.ts
@@ -1,6 +1,6 @@
 import { json, type RequestHandler } from '@sveltejs/kit';
-import { getVoteStatsByTaskId } from '$features/votes/services/vote_statistics';
-import { getVoteGrade } from '$features/votes/services/vote_grade';
+import { getVoteStatsByTaskId } from '#features/votes/services/vote_statistics.js';
+import { getVoteGrade } from '#features/votes/services/vote_grade.js';
 
 export const GET: RequestHandler = async ({ url, locals }) => {
   const taskId = url.searchParams.get('taskId');
diff --git a/src/routes/problems/getMyVote/+server.ts b/src/routes/problems/getMyVote/+server.ts
index e0a5a20b2..48cde9f11 100644
--- a/src/routes/problems/getMyVote/+server.ts
+++ b/src/routes/problems/getMyVote/+server.ts
@@ -1,5 +1,5 @@
 import { json, type RequestHandler } from '@sveltejs/kit';
-import { getVoteGrade } from '$features/votes/services/vote_grade';
+import { getVoteGrade } from '#features/votes/services/vote_grade.js';
 
 export const GET: RequestHandler = async ({ url, locals }) => {
   const taskId = url.searchParams.get('taskId');
diff --git a/src/routes/problems/page_server.test.ts b/src/routes/problems/page_server.test.ts
index 81e69e83c..b1120d1b1 100644
--- a/src/routes/problems/page_server.test.ts
+++ b/src/routes/problems/page_server.test.ts
@@ -2,7 +2,7 @@ import { describe, test, expect, vi, beforeEach } from 'vitest';
 
 import { Roles } from '#lib/types/user.js';
 
-vi.mock('$features/votes/services/vote_statistics', () => ({
+vi.mock('#features/votes/services/vote_statistics.js', () => ({
   getVoteGradeStatistics: vi.fn(),
 }));
 
@@ -11,7 +11,7 @@ vi.mock('#lib/services/task_results.js', () => ({
   getTasksWithTagIds: vi.fn(),
 }));
 
-import * as voteStatsModule from '$features/votes/services/vote_statistics';
+import * as voteStatsModule from '#features/votes/services/vote_statistics.js';
 import * as taskCrud from '#lib/services/task_results.js';
 import { load } from './+page.server';
 
diff --git a/src/routes/sitemap.xml/+server.ts b/src/routes/sitemap.xml/+server.ts
index bc5272782..6287ad256 100644
--- a/src/routes/sitemap.xml/+server.ts
+++ b/src/routes/sitemap.xml/+server.ts
@@ -10,9 +10,9 @@ import { error } from '@sveltejs/kit';
 import type { RequestHandler } from '@sveltejs/kit';
 import * as sitemap from 'super-sitemap';
 
-import * as workBooksCrud from '$features/workbooks/services/workbooks';
+import * as workBooksCrud from '#features/workbooks/services/workbooks.js';
 
-import { getUrlSlugFrom } from '$features/workbooks/utils/workbooks';
+import { getUrlSlugFrom } from '#features/workbooks/utils/workbooks.js';
 import { INTERNAL_SERVER_ERROR } from '#lib/constants/http-response-status-codes.js';
 
 /**
diff --git a/src/routes/users/[username]/+page.server.ts b/src/routes/users/[username]/+page.server.ts
index 258330b7f..ee004f82f 100644
--- a/src/routes/users/[username]/+page.server.ts
+++ b/src/routes/users/[username]/+page.server.ts
@@ -2,7 +2,7 @@
 
 import * as userService from '#lib/services/users.js';
 import * as taskResultService from '#lib/services/task_results.js';
-import { getLoggedInUser } from '$features/auth/services/session_guards';
+import { getLoggedInUser } from '#features/auth/services/session_guards.js';
 
 import type { Roles } from '#lib/types/user.js';
 import type { TaskResult } from '#lib/types/task.js';
diff --git a/src/routes/users/edit/+page.server.ts b/src/routes/users/edit/+page.server.ts
index d491ba0b8..192ed5882 100644
--- a/src/routes/users/edit/+page.server.ts
+++ b/src/routes/users/edit/+page.server.ts
@@ -5,8 +5,8 @@ import type { Actions } from './$types';
 import type { Roles } from '#lib/types/user.js';
 
 import * as userService from '#lib/services/users.js';
-import * as verificationService from '$features/account/services/atcoder_verification';
-import { getLoggedInUser } from '$features/auth/services/session_guards';
+import * as verificationService from '#features/account/services/atcoder_verification.js';
+import { getLoggedInUser } from '#features/auth/services/session_guards.js';
 
 import {
   BAD_REQUEST,
diff --git a/src/routes/users/edit/+page.svelte b/src/routes/users/edit/+page.svelte
index 9e4481454..b3cd6dca8 100644
--- a/src/routes/users/edit/+page.svelte
+++ b/src/routes/users/edit/+page.svelte
@@ -1,8 +1,8 @@
 <script lang="ts">
   import { Tabs, TabItem, Alert } from 'flowbite-svelte';
 
-  import AtCoderVerificationForm from '$features/account/components/settings/AtCoderVerificationForm.svelte';
-  import AccountDeletionForm from '$features/account/components/delete/AccountDeletionForm.svelte';
+  import AtCoderVerificationForm from '#features/account/components/settings/AtCoderVerificationForm.svelte';
+  import AccountDeletionForm from '#features/account/components/delete/AccountDeletionForm.svelte';
   import ContainerWrapper from '#lib/components/ContainerWrapper.svelte';
   import FormWrapper from '#lib/components/FormWrapper.svelte';
   import LabelWrapper from '#lib/components/LabelWrapper.svelte';
diff --git a/src/routes/votes/+page.server.ts b/src/routes/votes/+page.server.ts
index 7a3b551b1..6b4ee150b 100644
--- a/src/routes/votes/+page.server.ts
+++ b/src/routes/votes/+page.server.ts
@@ -2,7 +2,7 @@ import type { PageServerLoad } from './$types';
 import {
   getAllTasksWithVoteInfo,
   type TaskWithVoteInfo,
-} from '$features/votes/services/vote_statistics';
+} from '#features/votes/services/vote_statistics.js';
 
 export const load: PageServerLoad = async ({ locals, setHeaders }) => {
   const session = await locals.auth.validate();
diff --git a/src/routes/votes/+page.svelte b/src/routes/votes/+page.svelte
index bd32162ad..a78acea3f 100644
--- a/src/routes/votes/+page.svelte
+++ b/src/routes/votes/+page.svelte
@@ -15,15 +15,15 @@
 
   import HeadingOne from '#lib/components/HeadingOne.svelte';
   import GradeLabel from '#lib/components/GradeLabel.svelte';
-  import RelativeEvaluationBadge from '$features/votes/components/RelativeEvaluationBadge.svelte';
+  import RelativeEvaluationBadge from '#features/votes/components/RelativeEvaluationBadge.svelte';
 
   import { TaskGrade } from '#lib/types/task.js';
-  import { MIN_VOTES_FOR_PROVISIONAL_GRADE } from '$features/votes/constants/statistics';
+  import { MIN_VOTES_FOR_PROVISIONAL_GRADE } from '#features/votes/constants/statistics.js';
 
   import { getContestNameLabel } from '#lib/contests/index.js';
   import { getTaskUrl, compareByContestIdAndTaskId } from '#lib/utils/task.js';
   import { filterTasksBySearch } from '#lib/utils/task_filter.js';
-  import { resolveDisplayGrade } from '$features/votes/utils/grade_options';
+  import { resolveDisplayGrade } from '#features/votes/utils/grade_options.js';
 
   const MAX_SEARCH_RESULTS = 20;
 
diff --git a/src/routes/votes/[slug]/+page.server.ts b/src/routes/votes/[slug]/+page.server.ts
index 023216952..4b16bcdb0 100644
--- a/src/routes/votes/[slug]/+page.server.ts
+++ b/src/routes/votes/[slug]/+page.server.ts
@@ -4,13 +4,13 @@ import { zod4 } from 'sveltekit-superforms/adapters';
 import type { Actions, PageServerLoad } from './$types';
 
 import { getTask } from '#lib/services/tasks.js';
-import { getVoteGrade } from '$features/votes/services/vote_grade';
+import { getVoteGrade } from '#features/votes/services/vote_grade.js';
 import {
   getVoteCountersByTaskId,
   getVoteStatsByTaskId,
-} from '$features/votes/services/vote_statistics';
-import { voteAbsoluteGrade } from '$features/votes/actions/vote_actions';
-import { voteAbsoluteGradeSchema } from '$features/votes/zod/schema';
+} from '#features/votes/services/vote_statistics.js';
+import { voteAbsoluteGrade } from '#features/votes/actions/vote_actions.js';
+import { voteAbsoluteGradeSchema } from '#features/votes/zod/schema.js';
 import { BAD_REQUEST } from '#lib/constants/http-response-status-codes.js';
 
 export const load: PageServerLoad = async ({ locals, params }) => {
diff --git a/src/routes/votes/[slug]/+page.svelte b/src/routes/votes/[slug]/+page.svelte
index 42a8cd7d4..288728c8d 100644
--- a/src/routes/votes/[slug]/+page.svelte
+++ b/src/routes/votes/[slug]/+page.svelte
@@ -5,7 +5,7 @@
   import { Button, Tooltip } from 'flowbite-svelte';
   import FlaskConical from '@lucide/svelte/icons/flask-conical';
   import GradeLabel from '#lib/components/GradeLabel.svelte';
-  import RelativeEvaluationBadge from '$features/votes/components/RelativeEvaluationBadge.svelte';
+  import RelativeEvaluationBadge from '#features/votes/components/RelativeEvaluationBadge.svelte';
 
   import { TaskGrade } from '#lib/types/task.js';
   import {
@@ -15,13 +15,13 @@
     toChangeTextColorIfNeeds,
   } from '#lib/utils/task.js';
 
-  import VoteDonutChart from '$features/votes/components/VoteDonutChart.svelte';
-  import { qGrades, dGrades } from '$features/votes/utils/grade_options';
-  import { MIN_VOTES_FOR_PROVISIONAL_GRADE } from '$features/votes/constants/statistics';
+  import VoteDonutChart from '#features/votes/components/VoteDonutChart.svelte';
+  import { qGrades, dGrades } from '#features/votes/utils/grade_options.js';
+  import { MIN_VOTES_FOR_PROVISIONAL_GRADE } from '#features/votes/constants/statistics.js';
 
   import { EDIT_PROFILE_PAGE } from '#lib/constants/navbar-links.js';
-  import { buildLoginPath } from '$features/auth/utils/login';
-  import { buildSignupPath } from '$features/auth/utils/signup';
+  import { buildLoginPath } from '#features/auth/utils/login.js';
+  import { buildSignupPath } from '#features/auth/utils/signup.js';
 
   let { data } = $props();
 
diff --git a/src/routes/votes/page_server.test.ts b/src/routes/votes/page_server.test.ts
index 4e1922afa..2e7dfc951 100644
--- a/src/routes/votes/page_server.test.ts
+++ b/src/routes/votes/page_server.test.ts
@@ -2,11 +2,11 @@ import { describe, test, expect, vi, beforeEach } from 'vitest';
 
 import { Roles } from '#lib/types/user.js';
 
-vi.mock('$features/votes/services/vote_statistics', () => ({
+vi.mock('#features/votes/services/vote_statistics.js', () => ({
   getAllTasksWithVoteInfo: vi.fn(),
 }));
 
-import * as voteStatsModule from '$features/votes/services/vote_statistics';
+import * as voteStatsModule from '#features/votes/services/vote_statistics.js';
 import { load } from './+page.server';
 
 const mockGetAllTasksWithVoteInfo = vi.mocked(voteStatsModule.getAllTasksWithVoteInfo);
diff --git a/src/routes/workbooks/+page.server.ts b/src/routes/workbooks/+page.server.ts
index e36e8961a..f74bcf49d 100644
--- a/src/routes/workbooks/+page.server.ts
+++ b/src/routes/workbooks/+page.server.ts
@@ -2,14 +2,14 @@ import { error, redirect } from '@sveltejs/kit';
 
 import * as taskCrud from '#lib/services/tasks.js';
 import * as taskResultsCrud from '#lib/services/task_results.js';
-import { getLoggedInUser } from '$features/auth/services/session_guards';
-import * as workBooksCrud from '$features/workbooks/services/workbooks';
+import { getLoggedInUser } from '#features/auth/services/session_guards.js';
+import * as workBooksCrud from '#features/workbooks/services/workbooks.js';
 import {
   getWorkbooksByPlacement,
   getWorkBooksCreatedByUsers,
   getAvailableSolutionCategories,
   getSolutionCategoryMapByWorkbookId,
-} from '$features/workbooks/services/workbooks';
+} from '#features/workbooks/services/workbooks.js';
 
 import { Roles } from '#lib/types/user.js';
 import type { TaskGrade, TaskResult } from '#lib/types/task.js';
@@ -17,22 +17,22 @@ import {
   WorkBookTab,
   type WorkBookTab as WorkBookTabType,
   WorkBookType,
-} from '$features/workbooks/types/workbook';
+} from '#features/workbooks/types/workbook.js';
 import {
   type PlacementQuery,
   ALL_SOLUTION_CATEGORIES,
   type SelectedSolutionCategory,
   type SolutionCategory,
-} from '$features/workbooks/types/workbook_placement';
+} from '#features/workbooks/types/workbook_placement.js';
 
 import { isAdmin, canDelete } from '#lib/utils/authorship.js';
-import { buildTaskIdsFromWorkbooks } from '$features/workbooks/utils/workbooks';
+import { buildTaskIdsFromWorkbooks } from '#features/workbooks/utils/workbooks.js';
 import {
   parseWorkBookTab,
   parseWorkBookGrade,
   parseWorkBookCategory,
-} from '$features/workbooks/utils/workbook_url_params';
-import { parseWorkBookId } from '$features/workbooks/utils/workbook';
+} from '#features/workbooks/utils/workbook_url_params.js';
+import { parseWorkBookId } from '#features/workbooks/utils/workbook.js';
 
 import {
   BAD_REQUEST,
diff --git a/src/routes/workbooks/+page.svelte b/src/routes/workbooks/+page.svelte
index 9e2fa42c6..0d4bd83a9 100644
--- a/src/routes/workbooks/+page.svelte
+++ b/src/routes/workbooks/+page.svelte
@@ -12,18 +12,18 @@
     type WorkbooksList,
     WorkBookType,
     WorkBookTab,
-  } from '$features/workbooks/types/workbook';
-  import { type SelectedSolutionCategory } from '$features/workbooks/types/workbook_placement';
+  } from '#features/workbooks/types/workbook.js';
+  import { type SelectedSolutionCategory } from '#features/workbooks/types/workbook_placement.js';
 
   import HeadingOne from '#lib/components/HeadingOne.svelte';
-  import WorkbookTabItem from '$features/workbooks/components/list/WorkbookTabItem.svelte';
-  import WorkBookList from '$features/workbooks/components/list/WorkBookList.svelte';
+  import WorkbookTabItem from '#features/workbooks/components/list/WorkbookTabItem.svelte';
+  import WorkBookList from '#features/workbooks/components/list/WorkBookList.svelte';
 
   import {
     calcWorkBookGradeModes,
     buildTaskResultsByWorkBookId,
-  } from '$features/workbooks/utils/workbooks';
-  import { buildWorkbooksUrl } from '$features/workbooks/utils/workbook_url_params';
+  } from '#features/workbooks/utils/workbooks.js';
+  import { buildWorkbooksUrl } from '#features/workbooks/utils/workbook_url_params.js';
 
   const WORKBOOKS_URL_KEY = 'workbooks-last-url';
 
diff --git a/src/routes/workbooks/[slug]/+page.server.ts b/src/routes/workbooks/[slug]/+page.server.ts
index 85ad4d9d6..b190cb98e 100644
--- a/src/routes/workbooks/[slug]/+page.server.ts
+++ b/src/routes/workbooks/[slug]/+page.server.ts
@@ -4,16 +4,16 @@ import { zod4 } from 'sveltekit-superforms/adapters';
 
 import { Roles } from '#lib/types/user.js';
 
-import { getLoggedInUser } from '$features/auth/services/session_guards';
+import { getLoggedInUser } from '#features/auth/services/session_guards.js';
 import * as taskResultsCrud from '#lib/services/task_results.js';
 import * as action from '#lib/actions/update_task_result.js';
-import { getWorkbookWithAuthor } from '$features/workbooks/services/workbooks';
-import { getVoteGradeStatisticsForTaskIds } from '$features/votes/services/vote_statistics';
-import { voteAbsoluteGrade as voteAbsoluteGradeAction } from '$features/votes/actions/vote_actions';
-import { voteAbsoluteGradeSchema } from '$features/votes/zod/schema';
+import { getWorkbookWithAuthor } from '#features/workbooks/services/workbooks.js';
+import { getVoteGradeStatisticsForTaskIds } from '#features/votes/services/vote_statistics.js';
+import { voteAbsoluteGrade as voteAbsoluteGradeAction } from '#features/votes/actions/vote_actions.js';
+import { voteAbsoluteGradeSchema } from '#features/votes/zod/schema.js';
 
 import { isAdmin, canRead } from '#lib/utils/authorship.js';
-import { parseWorkBookId, parseWorkBookUrlSlug } from '$features/workbooks/utils/workbook';
+import { parseWorkBookId, parseWorkBookUrlSlug } from '#features/workbooks/utils/workbook.js';
 
 import { BAD_REQUEST, FORBIDDEN, NOT_FOUND } from '#lib/constants/http-response-status-codes.js';
 
diff --git a/src/routes/workbooks/[slug]/+page.svelte b/src/routes/workbooks/[slug]/+page.svelte
index 1dd083789..7e86dc037 100644
--- a/src/routes/workbooks/[slug]/+page.svelte
+++ b/src/routes/workbooks/[slug]/+page.svelte
@@ -15,16 +15,16 @@
   import UpdatingModal from '#lib/components/SubmissionStatus/UpdatingModal.svelte';
   import SubmissionStatusImage from '#lib/components/SubmissionStatus/SubmissionStatusImage.svelte';
   import ExternalLinkWrapper from '#lib/components/ExternalLinkWrapper.svelte';
-  import VotableGrade from '$features/votes/components/VotableGrade.svelte';
-  import PublicationStatusLabel from '$features/workbooks/components/shared/PublicationStatusLabel.svelte';
-  import CommentAndHint from '$features/workbooks/components/detail/CommentAndHint.svelte';
+  import VotableGrade from '#features/votes/components/VotableGrade.svelte';
+  import PublicationStatusLabel from '#features/workbooks/components/shared/PublicationStatusLabel.svelte';
+  import CommentAndHint from '#features/workbooks/components/detail/CommentAndHint.svelte';
   import { getBackgroundColorFrom } from '#lib/services/submission_status.js';
 
   import { addContestNameToTaskIndex } from '#lib/contests/index.js';
   import { getTaskUrl, removeTaskIndexFromTitle } from '#lib/utils/task.js';
 
   import type { TaskResult } from '#lib/types/task.js';
-  import type { WorkBookTaskBase } from '$features/workbooks/types/workbook';
+  import type { WorkBookTaskBase } from '#features/workbooks/types/workbook.js';
 
   let { data } = $props();
 
diff --git a/src/routes/workbooks/create/+page.server.ts b/src/routes/workbooks/create/+page.server.ts
index 6f602bf9e..559cc6a9d 100644
--- a/src/routes/workbooks/create/+page.server.ts
+++ b/src/routes/workbooks/create/+page.server.ts
@@ -3,9 +3,12 @@ import { superValidate } from 'sveltekit-superforms/server';
 import { zod4 } from 'sveltekit-superforms/adapters';
 
 import * as tasksCrud from '#lib/services/tasks.js';
-import { ensureSessionOrRedirect, getLoggedInUser } from '$features/auth/services/session_guards';
-import * as workBooksCrud from '$features/workbooks/services/workbooks';
-import { workBookSchema } from '$features/workbooks/zod/schema';
+import {
+  ensureSessionOrRedirect,
+  getLoggedInUser,
+} from '#features/auth/services/session_guards.js';
+import * as workBooksCrud from '#features/workbooks/services/workbooks.js';
+import { workBookSchema } from '#features/workbooks/zod/schema.js';
 
 import { Roles } from '#lib/types/user.js';
 
diff --git a/src/routes/workbooks/create/+page.svelte b/src/routes/workbooks/create/+page.svelte
index 46793abf8..78aaa6e2e 100644
--- a/src/routes/workbooks/create/+page.svelte
+++ b/src/routes/workbooks/create/+page.svelte
@@ -2,9 +2,9 @@
   import { superForm } from 'sveltekit-superforms/client';
 
   import type { Task } from '#lib/types/task.js';
-  import { WorkBookType, type WorkBookTasksBase } from '$features/workbooks/types/workbook';
+  import { WorkBookType, type WorkBookTasksBase } from '#features/workbooks/types/workbook.js';
 
-  import WorkBookForm from '$features/workbooks/components/shared/WorkBookForm.svelte';
+  import WorkBookForm from '#features/workbooks/components/shared/WorkBookForm.svelte';
 
   let { data } = $props();
 
diff --git a/src/routes/workbooks/edit/[slug]/+page.server.ts b/src/routes/workbooks/edit/[slug]/+page.server.ts
index 3eed6841d..5c57939c5 100644
--- a/src/routes/workbooks/edit/[slug]/+page.server.ts
+++ b/src/routes/workbooks/edit/[slug]/+page.server.ts
@@ -3,14 +3,14 @@ import { superValidate } from 'sveltekit-superforms/server';
 import { zod4 } from 'sveltekit-superforms/adapters';
 
 import { Roles } from '#lib/types/user.js';
-import { workBookSchema } from '$features/workbooks/zod/schema';
+import { workBookSchema } from '#features/workbooks/zod/schema.js';
 
 import * as tasksCrud from '#lib/services/tasks.js';
-import { getLoggedInUser } from '$features/auth/services/session_guards';
-import * as workBooksCrud from '$features/workbooks/services/workbooks';
+import { getLoggedInUser } from '#features/auth/services/session_guards.js';
+import * as workBooksCrud from '#features/workbooks/services/workbooks.js';
 
 import { canEdit, isAdmin } from '#lib/utils/authorship.js';
-import { parseWorkBookId, parseWorkBookUrlSlug } from '$features/workbooks/utils/workbook';
+import { parseWorkBookId, parseWorkBookUrlSlug } from '#features/workbooks/utils/workbook.js';
 
 import {
   BAD_REQUEST,
diff --git a/src/routes/workbooks/edit/[slug]/+page.svelte b/src/routes/workbooks/edit/[slug]/+page.svelte
index 7935f4aaa..1d9891191 100644
--- a/src/routes/workbooks/edit/[slug]/+page.svelte
+++ b/src/routes/workbooks/edit/[slug]/+page.svelte
@@ -2,10 +2,10 @@
   import { superForm } from 'sveltekit-superforms/client';
 
   import ErrorMessageAndReturnButton from '#lib/components/Messages/ErrorMessageAndReturnButton.svelte';
-  import WorkBookForm from '$features/workbooks/components/shared/WorkBookForm.svelte';
+  import WorkBookForm from '#features/workbooks/components/shared/WorkBookForm.svelte';
 
   import type { Task } from '#lib/types/task.js';
-  import type { WorkBookTasksBase } from '$features/workbooks/types/workbook';
+  import type { WorkBookTasksBase } from '#features/workbooks/types/workbook.js';
 
   import { FORBIDDEN } from '#lib/constants/http-response-status-codes.js';
   import { WORKBOOKS_PAGE } from '#lib/constants/navbar-links.js';
diff --git a/src/test/lib/services/tasks.test.ts b/src/test/lib/services/tasks.test.ts
index 7267b6833..517ea30cf 100644
--- a/src/test/lib/services/tasks.test.ts
+++ b/src/test/lib/services/tasks.test.ts
@@ -19,12 +19,12 @@ vi.mock('#lib/server/tasks/cache.js', () => ({
   invalidateTaskCaches: vi.fn(),
 }));
 
-vi.mock('$features/votes/server/cache', () => ({
+vi.mock('#features/votes/server/cache.js', () => ({
   invalidateVoteCaches: vi.fn(),
 }));
 
 import db from '#lib/server/database.js';
-import { invalidateVoteCaches } from '$features/votes/server/cache';
+import { invalidateVoteCaches } from '#features/votes/server/cache.js';
 
 describe('updateTask', () => {
   const mockDb = db as unknown as { task: { update: ReturnType<typeof vi.fn> } };
diff --git a/src/test/lib/utils/task.test.ts b/src/test/lib/utils/task.test.ts
index efd1546b5..acde52276 100644
--- a/src/test/lib/utils/task.test.ts
+++ b/src/test/lib/utils/task.test.ts
@@ -15,7 +15,7 @@ import { taskResultsForTaskTableHeaderName } from './test_cases/task_table_heade
 
 import { ContestType } from '#lib/contests/types/contest.js';
 import { type TaskResult, type TaskResults } from '#lib/types/task.js';
-import type { WorkBookTaskBase } from '$features/workbooks/types/workbook';
+import type { WorkBookTaskBase } from '#features/workbooks/types/workbook.js';
 
 import {
   getTaskUrl,
diff --git a/src/test/lib/utils/test_cases/task_results.ts b/src/test/lib/utils/test_cases/task_results.ts
index 0ae90db05..90bf28e71 100644
--- a/src/test/lib/utils/test_cases/task_results.ts
+++ b/src/test/lib/utils/test_cases/task_results.ts
@@ -1,6 +1,6 @@
 import { TaskGrade } from '#lib/types/task.js';
 import type { TaskResult, TaskResults } from '#lib/types/task.js';
-import type { WorkBookTaskBase } from '$features/workbooks/types/workbook';
+import type { WorkBookTaskBase } from '#features/workbooks/types/workbook.js';
 
 const userId2 = '2';
 const userId3 = '3';
diff --git a/svelte.config.js b/svelte.config.js
index 9d7abd0eb..322d27072 100644
--- a/svelte.config.js
+++ b/svelte.config.js
@@ -1,4 +1,3 @@
-import { resolve } from 'path';
 import adapter from '@sveltejs/adapter-vercel';
 import { vitePreprocess } from '@sveltejs/vite-plugin-svelte';
 
@@ -16,15 +15,7 @@ const config = {
       memory: 3008, // To avoid OOM errors on /workbooks/{slug}
       maxDuration: 30,
     }),
-    // See:
-    // https://kit.svelte.dev/docs/configuration#alias
-    alias: {
-      '@': resolve('./src'),
-      $lib: resolve('./src/lib'),
-      '$lib/*': resolve('./src/lib/*'),
-      $features: resolve('./src/features'),
-      '$features/*': resolve('./src/features/*'),
-    },
+    // Module paths use package.json#imports (#lib, #features); SvelteKit 3 deprecates kit.alias
   },
 
   compilerOptions: {
diff --git a/tsconfig.json b/tsconfig.json
index 79fba7e5b..91c9443c9 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -16,7 +16,7 @@
     "types": ["node", "vitest/globals"], // Note: "node" is required because "types" is replaced (not merged) when extending tsconfig
     "verbatimModuleSyntax": true
   },
-  // Path aliases are handled by https://kit.svelte.dev/docs/configuration#alias
+  // Module paths are resolved by package.json#imports (#lib, #features), not path aliases
   //
   // If you want to overwrite includes/excludes, make sure to copy over the relevant includes/excludes
   // from the referenced tsconfig.json - TypeScript does not merge them in