feat: add "worker" exports condition (#14779)

Author: bluwy

.changeset/calm-shrimps-remain.md

@@ -0,0 +1,5 @@
+---
+'svelte': minor
+---
+
+feat: add "worker" exports condition to better support bundling for worker-based environments

packages/svelte/package.json

@@ -21,6 +21,7 @@
   "exports": {
     ".": {
       "types": "./types/index.d.ts",
+      "worker": "./src/index-server.js",
       "browser": "./src/index-client.js",
       "default": "./src/index-server.js"
     },
@@ -64,6 +65,7 @@
     },
     "./legacy": {
       "types": "./types/index.d.ts",
+      "worker": "./src/legacy/legacy-server.js",
       "browser": "./src/legacy/legacy-client.js",
       "default": "./src/legacy/legacy-server.js"
     },
@@ -73,6 +75,7 @@
     },
     "./reactivity": {
       "types": "./types/index.d.ts",
+      "worker": "./src/reactivity/index-server.js",
       "browser": "./src/reactivity/index-client.js",
       "default": "./src/reactivity/index-server.js"
     },
@@ -86,6 +89,7 @@
     },
     "./store": {
       "types": "./types/index.d.ts",
+      "worker": "./src/store/index-server.js",
       "browser": "./src/store/index-client.js",
       "default": "./src/store/index-server.js"
     },