perf(mobile): isolate iOS Live Activity imports

[juliusmarminge]

The shared notification registration module eagerly imports the iOS Live Activity layout, bringing expo-widgets and 81 SwiftUI modules into Android. Put layout access behind an iOS adapter and an unsupported-platform adapter with erased type imports. Keep registration, retry handling, reconciliation, and sign-out cleanup in the shared module.

Verification:

• Existing registration, Live Activity preferences, and widget tests: 52 passed; mobile workspace typecheck and targeted lint passed.
• Production Android Hermes export: 20,193,450 → 20,054,819 bytes, saving 138,631 bytes at this layer.
• Final Android release source maps contain zero expo-widgets modules, zero SwiftUI modules, and no AgentActivity layout. iOS retains the layout and all 81 SwiftUI modules.

This changes module ownership with no intended visual or lifecycle change. Release output and existing behavior tests provide the evidence; native app download size was not measured.
Based on #12379.

Runtime verification on September 18, 2026: the integrated stack at 47a3dcb was tested on an iPhone 17 Pro simulator (iOS 27.0) and T3Code_API_36_1 emulator (Android 16.0), one at a time. Compatible development clients were built and installed from this checkout, then connected to a disposable environment with seeded Git projects. Coverage included Home/list rendering, thread navigation, file search and word wrap, terminal menus and session selection, review diff selection, archive menus, and Settings Add Environment / scanner open and close. Temporary connections were removed and the devices and test servers were stopped. Tablet layouts, QR decoding, and Live Activity start/update/stop were not exercised. Screenshots use seeded demo content; any test counts in demo messages or terminal output are fixture text, not validation results.

iOS loaded the widget bundle, and Android launched with its platform no-op implementation. Live Activity lifecycle behavior was not exercised; production module ownership remains the evidence that Android excludes those imports.

The pre-existing iOS archive keyboard issue and stale-connection loading limitation are recorded with comparison evidence in #12399.

Prepared with Codex.

Summary by CodeRabbit

• New Features

  • Added support for starting and retrieving agent Live Activities on iOS.
  • Added platform-aware handling for agent activity requests across supported environments.

• Bug Fixes

  • Improved local and remote agent activity activation so requests are handled safely when Live Activities are unavailable.

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	—	13.5 KiB	—	15.1 KiB	✅
Codex	Thread snapshot wire	—	7.1 KiB	—	7.3 KiB	✅
Codex	Live turn WebSocket wire	—	6.5 KiB	—	7.8 KiB	✅
Codex	Live turn WebSocket decoded	—	56.3 KiB	—	66.4 KiB	✅
Codex	Live turn messages	—	10	—	21	✅
Claude	Total thread wire	—	13.5 KiB	—	15.1 KiB	✅
Claude	Thread snapshot wire	—	7.1 KiB	—	7.3 KiB	✅
Claude	Live turn WebSocket wire	—	6.4 KiB	—	7.8 KiB	✅
Claude	Live turn WebSocket decoded	—	57.0 KiB	—	66.4 KiB	✅
Claude	Live turn messages	—	9	—	21	✅

Baseline: unavailable · PR result: c3bb164 · 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.

Approvability

Verdict: Approved at c3bb164

Macroscope's review found this PR approvable — This is a contained platform-import refactor that preserves the existing iOS Live Activity implementation while removing iOS-only runtime code from Android’s bundle. Shared registration behavior remains unchanged for supported paths, with tests updated for the adapter boundary.

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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: Team

Run ID: 40b5fb97-f736-4767-a822-6d9d3ef6e8df

📥 Commits

Reviewing files that changed from the base of the PR and between 8bcd416 and c3bb164.

📒 Files selected for processing (4)

• apps/mobile/src/features/agent-awareness/agentLiveActivity.ios.ts
• apps/mobile/src/features/agent-awareness/agentLiveActivity.ts
• apps/mobile/src/features/agent-awareness/remoteRegistration.test.ts
• apps/mobile/src/features/agent-awareness/remoteRegistration.ts

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📝 Walkthrough

Walkthrough

The change adds typed live activity helpers for iOS and other platforms. Local registration, cleanup, and remote reconciliation now use these helpers. Tests mock the named helper exports.

Changes

Agent Live Activity integration

Layer / File(s)	Summary
Live activity helper APIs apps/mobile/src/features/agent-awareness/agentLiveActivity.ts, apps/mobile/src/features/agent-awareness/agentLiveActivity.ios.ts	Adds typed helpers for retrieving and starting agent live activities. The iOS helpers delegate to AgentActivity; the base helpers return no activities and null.
Local registration integration apps/mobile/src/features/agent-awareness/remoteRegistration.ts	Routes local activity lookup, creation, and cleanup through the helper APIs. Local registration stops when activity creation returns no activity.
Remote reconciliation and test wiring apps/mobile/src/features/agent-awareness/remoteRegistration.ts, apps/mobile/src/features/agent-awareness/remoteRegistration.test.ts	Routes remote activity discovery, race-condition checks, and priming through the helpers. Updates the test mock to expose the named helper functions.

Priority: ⬇️ Low

Estimated code review effort: 3 (Moderate) | ~20 minutes

Change: Refactor

Merge Risk: ⚪ Minimal · up to c3bb1

No actionable compatibility, runtime, security, or data-integrity issue was found in this change.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 7 functions across 4 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
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.
Title check	✅ Passed	The title clearly and concisely describes the main change: isolating iOS Live Activity imports in the mobile application.
Description check	✅ Passed	The description clearly explains the change, rationale, verification results, scope, and known testing limits. It does not use the template headings or checklist, but it provides the required informat…

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