fix(usage): keep cached usage-limits commands local

[Lucenx9]

What changed

T3's /usage-limits command can become an ordinary provider prompt when its catalog survives a reconnect but its external quota data does not.

Mark T3's command with optional source: "t3" metadata and use it in the web, desktop, and mobile composers. Existing threads keep the command local even when limits are unavailable. Mobile New Task keeps it out of the send queue.

Why

The cache intentionally omits external quota snapshots while retaining the provider catalog. Command ownership must survive that gap without inventing quota data or claiming a provider's own command with the same name.

The existing data-based check remains as a fallback for older servers. Old caches without the marker need one connection to an updated server; this change cannot distinguish them from native commands while offline.

flowchart LR
    catalog["Cached command: source=t3"] --> web["Web and desktop"]
    catalog --> thread["Mobile thread"]
    catalog --> draft["Mobile New Task"]
    web --> local["Handle locally"]
    thread --> local
    draft --> guard["Do not queue a turn"]

Loading

UI changes

Real web client in Chromium, with an isolated project and controlled quota responses. PNGs are 2560 × 1600. The before capture uses the original ownership check with the same fixture. Turn-start requests are recorded and stopped at the browser boundary, so no agent runs.

Before	After
Before video	After video

Verification

• 75 focused tests pass across contracts, shared usage helpers, the mobile command menu, and server config subscriptions.
• The new catalog-decoding regression failed before the schema fix.
• Browser checks cover typed and menu-selected commands without quota data, available external limits, and an unmarked native command with the identical label. Local commands dispatch zero turns; the native command still reaches the send boundary.
• Typechecks pass for contracts, shared, web, and mobile. Targeted lint has no errors or warnings on changed lines. Formatting and git diff --check pass.
• Fallow's single-thread audit passes with no newly introduced findings. No repository-wide checks ran.

Desktop shares the web composer. Mobile is covered by focused tests and typechecking, not a device run. No product defaults or diagnostic suppressions change.

Checklist

• This PR is small and focused
• I explained what changed and why
• I included before/after screenshots for UI changes
• I included videos for the interaction change

Model: GPT-5. Harness: Codex in T3 Code.

Summary by CodeRabbit

• Bug Fixes

  • The /usage-limits command now remains available while usage-limit information reconnects.
  • Improved handling distinguishes locally available usage-limit commands from provider-provided commands.
  • Cached commands are preserved across provider status updates and older server data formats.

• Reliability

  • Usage-limit command availability and provider command data are now handled more consistently across mobile and web experiences.

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[chatgpt-codex-connector]

Codex Review Summary

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-08T17:27:32.254111Z	3e675e6	PR opened

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[macroscopeapp]

Approvability

Verdict: Approved at 3e675e6

Macroscope's review found this PR approvable — This is a focused compatibility bug fix that preserves local /usage-limits ownership across cached provider catalogs while keeping native provider commands unchanged. The additive metadata and targeted tests keep the runtime impact limited to composer command routing.

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No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Advanced

Run ID: 7713e8d3-3004-4085-bf7c-a5d922820183

📥 Commits

Reviewing files that changed from the base of the PR and between 12391bd and 3e675e6.

📒 Files selected for processing (9)

• apps/mobile/src/features/threads/NewTaskDraftScreen.tsx
• apps/mobile/src/features/threads/ThreadComposer.tsx
• apps/mobile/src/features/threads/use-composer-command-menu.test.ts
• apps/server/src/server.test.ts
• apps/web/src/components/ChatView.tsx
• packages/contracts/src/server.test.ts
• packages/contracts/src/server.ts
• packages/shared/src/usageLimits.test.ts
• packages/shared/src/usageLimits.ts

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📝 Walkthrough

Walkthrough

Adds local ownership metadata for the usage-limits command, preserves it through provider decoding, supports legacy providers, and updates mobile and web availability checks.

Changes

Usage-limits command ownership

Layer / File(s)	Summary
Ownership contract and detection packages/contracts/src/server.ts, packages/contracts/src/server.test.ts, packages/shared/src/usageLimits.ts, packages/shared/src/usageLimits.test.ts	ServerProviderSlashCommand accepts source: "t3". hasLocalUsageLimitsCommand detects locally owned commands and falls back to legacy data-based detection. Tests cover decoding and ownership cases.
Server provider payloads apps/server/src/server.test.ts	Provider status expectations include source: "t3" on injected usage-limits commands.
Client command availability apps/mobile/src/features/threads/*, apps/mobile/src/features/threads/use-composer-command-menu.test.ts, apps/web/src/components/ChatView.tsx	Mobile and web use hasLocalUsageLimitsCommand with the selected provider status. Command-menu tests cover local and non-local commands.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Merge Risk: ⚪ Minimal · up to 3e675

This change keeps locally handled usage-limits commands available across reconnects while retaining compatibility with older server catalogs. The ownership contract, fallback behavior, and affected client flows are covered, with no concrete merge-blocking risk identified.

Suggested reviewers: juliusmarminge

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 4 functions across 9 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely describes the primary change: keeping cached usage-limits commands local.
Description check	✅ Passed	The description explains what changed, why it changed, the UI impact, verification results, and checklist status. It closely matches the required template and provides relevant testing limitations.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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