feat: implement STT and TTS foundation using Expo libraries

[Debashich]

Basic Testing Checklist

• Onboarding: "Welcome to Clara" plays upon OnboardingScreen mount (audible at 50%+ device volume).
• Prompts: Mic button triggers "Go ahead, speak now" before listening begins.
• Auto-play: Assistant responses speak automatically immediately after a message is sent.

Mic Button Behavior

• Activation Flow: Press mic → TTS prompt plays → 100ms delay → STT activates (red indicator visible).
• Real-time Feedback: Transcript appears on-screen while speaking into the device.
• Toggle: Pressing again or releasing stops the listening state.
• Audio Quality: Zero audio overlap or crackling between the end of TTS and the start of STT. [1, 2]

Expected Console Logs

[TTS] Initializing TTS engine...
[TTS] Speaking: Welcome to Clara
[TTS] Speech started
[STT] Checking microphone permission...
[STT] Starting voice recognition...
[STT] Transcript captured: [user speech]
[TTS] Speech completed

[Copilot]

Pull request overview

Implements an initial Speech-to-Text (STT) and Text-to-Speech (TTS) foundation for the app using Expo libraries, wiring speech prompts and voice capture into onboarding and the home chat flow.

Changes:

• Added TTS/STT service wrappers and hooks (useTTS, useSTT) backed by expo-speech and expo-speech-recognition.
• Integrated speech behaviors into OnboardingScreen (welcome + mic prompt + transcript-to-answer) and HomeScreen (mic prompt + transcript-to-message + auto TTS reply).
• Updated project config: Android permissions, new dependencies, and a postinstall script to patch module tsconfigs.

Reviewed changes

Copilot reviewed 11 out of 12 changed files in this pull request and generated 12 comments.

Show a summary per file

File	Description
test.md	Added a planning/architecture doc for speech structure and phases.
src/services/speech/tts.ts	Implements Expo Speech wrapper with initialization/logging and speech control.
src/services/speech/stt.ts	Implements Expo speech-recognition wrapper with permission handling and event listeners.
src/hooks/useTTS.ts	Hook to initialize and expose speak/stop APIs.
src/hooks/useSTT.ts	Hook to manage listening state and transcript updates via STT service.
src/screens/OnboardingScreen.tsx	Adds welcome TTS, mic-driven STT, and transcript display/answer updates.
src/screens/HomeScreen.tsx	Adds mic-driven STT, auto-send from transcript, and auto TTS assistant reply.
src/constants/voice.ts	Introduces shared TTS voice configuration.
scripts/postinstall-fixes.js	Adds install-time patching of dependency tsconfig files.
package.json	Adds speech deps + postinstall script + related tooling deps.
app.json	Adds Android permissions required/used by speech features.

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[Copilot]

Just as a heads up, I was blocked by some firewall rules while working on your feedback. Expand below for details.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• api.expo.dev
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node node /home/REDACTED/work/Clara/Clara/node_modules/.bin/expo start --web --non-interactive --port 8081 de/node/bin/git (dns block)
• cdp.expo.dev
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node node /home/REDACTED/work/Clara/Clara/node_modules/.bin/expo start --web --non-interactive --port 8081 de/node/bin/git (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

[Debashich]

@copilot verify all updates

[Copilot]

@copilot verify all updates

Verified all implemented updates on 5ca7707 (plus prior related commits in this branch):

• Mic flow sequencing is correct in Onboarding and Home (TTS prompt completes → 100ms delay → STT starts).
• Latest workflow runs show no failed jobs.
• Local TypeScript validation passes (npx tsc --noEmit).

Screenshot: