feat(spike): voice dictation + photo capture integration for iOS 26

[obvious-autobuild]

Human author: Gilbert Polanco (gilbertpolanco42@gmail.com)

Why

The T3 dictation findings (art_tXjksHOh) recommended adopting @react-native-ai/apple for on-device record-then-transcribe and expo-image-picker + Convex storage for photos, but only after proving the dependency set installs coherently, the native surface is shaped correctly, and the flow is unit-testable without an iOS 26 device. This spike delivers that proof — isolated under spikes/voice-photo/ so arena candidates are untouched.

What

• Pinned dependency set (all versions retrieved from npm this session): @react-native-ai/apple@0.12.0 (verified MIT TurboModule, peer react-native >= 0.76), Expo SDK 57 line (expo@57.0.23, expo-audio@57.0.5, expo-file-system@57.0.7, expo-image-picker@57.0.18), react-native@0.86.3 + react@19.2.3 (New Architecture), effect@4.0.0-rc.115 (the contract's pin), convex@1.46.0. Exact pins and rationale in the README table. t3code's 194-line pnpm patch is deliberately not adopted (test unpatched first, per the findings).
• API-surface correction: the findings described isAvailable() as no-arg; the actual 0.12.0 surface (read from the package's own .d.ts) is isAvailable(language: string): boolean, prepare(language), transcribe(ArrayBufferLike, language) → { segments, duration }. The adapter mirrors this structurally.
• VoiceTranscriber port (src/transcription/): typed error taxonomy (unavailable / unsupported-locale / preparation-failed / transcription-failed / cancelled), AbortSignal cancellation, live Apple adapter with preserved cause wrapping, deterministic FakeVoiceTranscriber, and platform wiring where Android/web resolve to null (UI hides dictation) — the graceful-degradation shape from the findings.
• Photo → Convex flow (src/photo/): the 3-request pattern from docs.convex.dev (generateUploadUrl mutation → POST bytes → commit mutation) with an injected transport, so the whole flow is unit-testable without a backend. A reference convex/photoStorage.ts module shows contract-mapped validators; production tables/auth scoping belong to the future app scaffold.
• Contract alignment: src/contract/schema.ts is a spike-local mock of the published contract art_I2TCG08V (the contract's own swap-the-import rule; packages/domain does not exist yet). Wire conversion goes through the contract's decodeUnknownSync/encodeSync. No photo↔Entry linkage field was added — the v0.1 contract has none and the spike may not extend it (flagged for the contract thread).
• Docs: Expo config wiring (plugin props verified from the pinned packages' own plugin sources), custom dev-client build note (Expo Go will not work — Swift pod), MIT attribution in NOTICE.md for adapted t3code shapes, and a 10-item device-proof checklist.

How to Review

Key files: src/transcription/apple.ts (adapter), src/photo/photoStorage.ts (upload flow), convex/photoStorage.ts (reference validators), src/contract/schema.ts (contract mock), README.md (pins, config, checklist).

Intentionally excluded: live streaming transcription (batch-only MVP per the findings), the contract extension proposal (goes to the contract thread), the monorepo app scaffold, and any CI changes outside spikes/voice-photo/ — CI here is the repo's existing PR pipeline running typecheck/tests on the spike package.

Test Evidence

• vitest run: 38/38 green (transcription adapter + fake + cancellation, contract decode/encode, photo upload ordering, wire conversion, failure wrapping).
• tsc --noEmit: strict-mode clean, including the live adapter compiled against the real package types and the convex reference module.
• npm ci from the committed lockfile: 520 packages, no conflicts (the CI-equivalent local gate).

Device-proof gap (no device evidence claimed)

The sandbox cannot run an iOS 26 device, a custom dev-client build, real microphone/photo permission prompts, or a live Convex deployment. The README carries an explicit 10-item device-proof checklist stating what must be verified on hardware before this architecture ships — none of it is claimed as verified here.

🔗 Obvious Project · 🧵 Obvious Thread

CI note (pre-existing, not introduced here)

The Typecheck, test, build check fails at Install dependencies with ERR_PNPM_NO_LOCKFILE. This is structural on the base branch, not caused by this PR: the workflow's own header says the package-level steps "require the monorepo scaffold (root package.json, pnpm-lock.yaml, turbo tasks) which lands via feat/monorepo-scaffold. Until that PR merges and this branch is rebased, those steps are expected to fail here." Verified this session: the base tip (ecf4018) has no root pnpm-lock.yaml, and this PR's diff touches zero files outside spikes/voice-photo/ (the spike carries its own npm lockfile and passes its own gates locally: npm ci → 520 packages, 38/38 tests, strict tsc clean). Once the scaffold merges, this branch will rebase so the check runs green here too.