refactor(mobile): share theme mapping across Android controls

[juliusmarminge]

Design-system progress

API adoption and Pen rendering are tracked separately. This is cumulative through this PR, not a claim that all native renderers are finished.

Pen component	After this PR
Host / native theme	Colors only; native typography and shapes left
List / Section / Row	Shared RN rows; native Form / ListItems left
Toggle	Native switches; Android checkmark treatment left
Segmented	Later in stack
Menu	Later in stack
Sheet	Later in stack
Dialog	Later in stack
SearchField	Later in stack
Button / IconButton	Later in stack
Chip	Shared RN chip; native Android variants left
Toast	Later in stack
FAB	Later in stack
Toolbar	Later in stack
AppBar	Later in stack
Picker / Slider / Stepper	Partial; iOS native slider and picker family left
Progress / EmptyState	Later in stack
Typography / shapes / motion	Later in stack
Split / list-detail / rail	Deferred broader layout work

Custom Appearance cards stay. Segmented controls stay native. Composer, thread-row and task-tray redesigns remain deferred.

Problem

Android controls create separate Compose Hosts, which can use a generated Material palette instead of the selected app theme. Radio indicators work around this by drawing a custom control for every non-system theme.

Change

Use the shared themed Host in buttons, icon buttons, switches, radio indicators, loading indicators, confirmation dialogs, menus, and floating actions. Radio indicators can now use Compose for all themes. Existing cards, layouts, sizing, interactions, and explicit control colors stay in place. This applies through the existing shared components in settings, thread controls, and other screens.

Validation: Android native client rebuilt successfully; 65 focused theme/dependency tests, mobile typecheck, and targeted lint passed. React Doctor found no issues in the changed files (91/100). Verified radio selection in Keyboard, dialogs and menus, all six themes in light/dark, and switching to Material You. Radio indicators retain the existing text-accent contrast. iOS is unchanged.

Scope and approval

The external-contributor triaged-issue requirement does not apply to this maintainer-authored work. It was requested by Julius as the next mobile design-system layer, retaining custom cards and screen layouts. Scope is the existing Android controls listed above; iOS is unchanged. The theme matrix and before/after captures support human visual review. Macroscope flags this cross-cutting UI change for human review; this PR is not approved to merge.

Model: GPT-6.1. Harness: Codex.

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[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

ℹ️ No successful main baseline artifact is available yet. This run establishes the initial measurement.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	—	5.0 KiB	—	6.8 KiB	✅
Codex	Thread snapshot wire	—	3.8 KiB	—	4.9 KiB	✅
Codex	Live turn WebSocket wire	—	1.2 KiB	—	2.0 KiB	✅
Codex	Live turn WebSocket decoded	—	20.9 KiB	—	29.3 KiB	✅
Codex	Live turn messages	—	2	—	8	✅
Claude	Total thread wire	—	5.0 KiB	—	6.8 KiB	✅
Claude	Thread snapshot wire	—	3.8 KiB	—	4.9 KiB	✅
Claude	Live turn WebSocket wire	—	1.2 KiB	—	2.0 KiB	✅
Claude	Live turn WebSocket decoded	—	21.2 KiB	—	29.3 KiB	✅
Claude	Live turn messages	—	2	—	8	✅

Baseline: unavailable · PR result: 583aaf7 · 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: 108.5 KiB
• Claude decoded thread snapshot: 108.8 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 change applies a new resolved Material palette to many existing Android controls and switches custom-theme radio indicators to Compose rendering. Because it changes user-visible behavior across dialogs, menus, actions, switches, and buttons, the cross-cutting runtime impact warrants human review.

No code changes detected at 583aaf7. Prior analysis still applies.

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[coderabbitai]

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📥 Commits

Reviewing files that changed from the base of the PR and between b62b3b9 and 583aaf7.

📒 Files selected for processing: 1

• apps/mobile/src/components/Button.android.tsx

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📝 Walkthrough

Android components now use NativeThemeHost instead of Compose Host. Most components no longer pass an explicit host colorScheme. MaterialRadioIndicator always renders an Expo RadioButton, and SliderRow imports the Android-specific theme host module.

Changes: Android theme host and controls

Layer / File(s)	Summary
Replace Compose Host wrappers apps/mobile/src/components/AppActivityIndicator.android.tsx, apps/mobile/src/components/MaterialConfirmDialog.android.tsx, apps/mobile/src/components/MaterialFloatingActionButton.android.tsx, apps/mobile/src/components/MaterialIconButton.android.tsx, apps/mobile/src/components/MaterialMenuPopup.android.tsx, apps/mobile/src/components/MaterialScrollComposeButton.android.tsx, apps/mobile/src/components/MaterialSwitch.android.tsx, apps/mobile/src/components/SliderRow.android.tsx, apps/mobile/src/components/Button.android.tsx	These components use NativeThemeHost in place of Compose Host. Explicit host colorScheme props are removed where they were present. Existing layout and inset settings remain. SliderRow uses the Android-specific import.
Radio indicator rendering apps/mobile/src/components/MaterialRadioIndicator.android.tsx	The component always renders an Expo RadioButton inside NativeThemeHost. It uses control-theme colors when system colors are inactive and empty color overrides when they are active.

Priority: ➖ Normal

Estimated code review effort: 2 (Simple) | ~12 minutes

Change: Bug fix

Merge Risk: ⚪ Minimal · up to 583aa

The Android button now uses the shared theme host without a reported change to its colors or behavior. No actionable merge-blocking risk is established.

Pre-merge checks: 4

Check name	Status	Explanation
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.
Title check		The title clearly and concisely describes the main change: sharing theme mapping across Android controls.
Description check		The description covers the problem, implementation, scope, approval context, validation results, affected platforms, and visual evidence. Verification details are included under the Change section rat…

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