feat(mobile): add favorites to model picker

[juliusmarminge]

Mobile lacked model favorites even though the web picker already supports them.

Add a favorite button and Favorites filter to the mobile picker. Favorites sort ahead of other models while preserving catalog order within each provider. A favorited legacy model stays visible when legacy models are hidden. Rapid favorite taps use the latest stored preferences so neither update is lost. Favorites are stored on the device for now, as agreed; web and mobile favorites do not sync yet. The model rows retain a 44-point touch target without the extra vertical padding, and Android gets visible star icons.

Verification: 16 focused tests passed, mobile typecheck passed, and targeted lint reported no errors. The maintainer verified the picker on a physical iPhone and waived screenshot evidence.

Harness: Codex. Model slug omitted at maintainer request.

Summary by CodeRabbit

• New Features

  • Added the ability to favorite models from Thread Settings.
  • Favorites are saved on the device and remain available across sessions.
  • Added a Favorites filter with dedicated empty states and platform-appropriate controls.
  • Favorite models appear first while preserving catalog order.
  • Improved model-row controls with clearer selection, favorite status, accessibility feedback, and loading states.
  • Added Android fallback icons for outlined and filled star symbols.

• Bug Fixes

  • Fixed preference updates so rapid successive changes are preserved correctly.

[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	13.5 KiB	13.5 KiB	−10 B (−0.1%)	15.1 KiB	✅
Codex	Thread snapshot wire	7.1 KiB	7.1 KiB	−2 B (−0.0%)	7.3 KiB	✅
Codex	Live turn WebSocket wire	6.5 KiB	6.4 KiB	−8 B (−0.1%)	7.8 KiB	✅
Codex	Live turn WebSocket decoded	56.3 KiB	56.2 KiB	−44 B (−0.1%)	66.4 KiB	✅
Codex	Live turn messages	10	9	−1 (−10.0%)	21	✅
Claude	Total thread wire	13.5 KiB	13.5 KiB	−17 B (−0.1%)	15.1 KiB	✅
Claude	Thread snapshot wire	7.1 KiB	7.1 KiB	−1 B (−0.0%)	7.3 KiB	✅
Claude	Live turn WebSocket wire	6.4 KiB	6.4 KiB	−16 B (−0.2%)	7.8 KiB	✅
Claude	Live turn WebSocket decoded	57.0 KiB	57.0 KiB	0 B (0.0%)	66.4 KiB	✅
Claude	Live turn messages	9	9	0 (0.0%)	21	✅

Baseline: dd9528a · PR result: f8ea35b · Source CI: success

Scenario and decoded snapshot size

10 historical turns, 5 command tools per turn, 878.9 KiB retained MCP result per historical turn, and a 1.05 MiB retained result in the measured turn.

• Codex decoded thread snapshot: 113.9 KiB
• Claude decoded thread snapshot: 114.6 KiB

Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.

[macroscopeapp]

Approvability

Verdict: Not approved

Macroscope's review found this PR not approvable — This PR adds a persistent, user-facing favorites workflow to the mobile model picker, including new controls, filtering, ordering, legacy-model handling, and preference update logic. The change is localized and backward-compatible for existing data, but its multi-part runtime behavior is broader than a minor isolated adjustment.

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[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Team

Run ID: b9a828a7-631a-46b2-b506-a957c285144d

📥 Commits

Reviewing files that changed from the base of the PR and between dd9528a and f8ea35b.

📒 Files selected for processing (7)

• apps/mobile/src/components/AppSymbol.tsx
• apps/mobile/src/features/threads/ThreadSettingsSheet.tsx
• apps/mobile/src/features/threads/thread-settings-sheet-state.test.ts
• apps/mobile/src/features/threads/thread-settings-sheet-state.ts
• apps/mobile/src/persistence/mobile-preferences.ts
• apps/mobile/src/state/preferences.test.ts
• apps/mobile/src/state/preferences.ts

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📝 Walkthrough

Walkthrough

The mobile app now supports device-local model favorites. Favorites are sanitized and persisted by provider and model, ordered before other models, and exposed through thread settings controls and filters.

Changes

Model favorites

Layer / File(s)	Summary
Favorite preference contract and updates apps/mobile/src/persistence/mobile-preferences.ts, apps/mobile/src/state/preferences.ts, apps/mobile/src/state/preferences.test.ts	Preferences now store sanitized provider/model favorites. Functional updates preserve consecutive changes before persistence.
Favorite state utilities apps/mobile/src/features/threads/thread-settings-sheet-state.ts, apps/mobile/src/features/threads/thread-settings-sheet-state.test.ts	Favorite keys, toggling, provider-scoped identity, and catalog-relative ordering are implemented and tested.
Thread settings controls and filters apps/mobile/src/features/threads/ThreadSettingsSheet.tsx, apps/mobile/src/components/AppSymbol.tsx	Thread settings load and persist favorites, provide separate favorite controls, order favorite models first, support favorite filters on Android and iOS, and add Android star fallbacks.

Priority: ⬇️ Low

Estimated code review effort: 3 (Moderate) | ~25 minutes

Change: Feature

Sequence Diagram(s)

sequenceDiagram
  participant User
  participant ModelRow
  participant ThreadSettingsSheet
  participant MobilePreferencesStore
  User->>ModelRow: Toggle favorite
  ModelRow->>ThreadSettingsSheet: Invoke favorite callback
  ThreadSettingsSheet->>MobilePreferencesStore: Persist provider/model favorite
  MobilePreferencesStore-->>ThreadSettingsSheet: Return updated preferences
  ThreadSettingsSheet-->>ModelRow: Render updated favorite state

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Suggested reviewers: t3dotgg, maria-rcks

Merge Risk: ⚪ Minimal · up to f8ea3

No concrete merge-blocking risk remains from the reviewed favorites changes.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 38.46% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 13 functions across 7 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 main change: adding favorites to the mobile model picker.
Description check	✅ Passed	The description explains what changed, why mobile needed the feature, UI behavior, persistence scope, verification results, and the screenshot waiver. It does not use the template headings or include …
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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