feat(api): use Tencent 16k_zh_large ASR and remove local Whisper

Standardize ASR on Tencent's dialect-capable engine across all environments,
drop faster-whisper from dependencies and deployment images, and add an
expo-sqlite iOS vendor sync plus pod install in prebuild to prevent native
build failures after npm install.

Co-authored-by: Cursor <cursoragent@cursor.com>

app-expo/package.json

@@ -4,13 +4,14 @@
   "version": "1.2.0",
   "scripts": {
     "use-env": "node scripts/use-env.js",
+    "postinstall": "node scripts/ensure-expo-sqlite-ios.js",
     "prestart": "npm run use-env -- development",
     "start": "expo start",
     "start:staging": "npm run use-env -- staging && expo start",
     "start:prod": "npm run use-env -- production && expo start",
     "reset-project": "node ./scripts/reset-project.js",
     "android": "npm run use-env -- development && expo run:android",
-    "ios": "npm run use-env -- development && expo run:ios",
+    "ios": "npm run use-env -- development && node scripts/ensure-expo-sqlite-ios.js && expo run:ios",
     "ios:prebuild": "bash scripts/ios-prebuild.sh staging",
     "ios:prebuild:staging": "bash scripts/ios-prebuild.sh staging",
     "ios:prebuild:production": "bash scripts/ios-prebuild.sh production",

app-expo/scripts/ensure-expo-sqlite-ios.js

@@ -0,0 +1,51 @@
+/**
+ * expo-sqlite copies vendor/sqlite3/*.c into ios/ during `pod install` (see ExpoSQLite.podspec).
+ * After a fresh `npm install`, Xcode can fail with missing sqlite3.c until pods run.
+ * This script mirrors that copy so native builds work without an extra manual step.
+ */
+const fs = require('fs');
+const path = require('path');
+
+const appRoot = path.join(__dirname, '..');
+const pkgRoot = path.join(appRoot, 'node_modules', 'expo-sqlite');
+
+function readUseLibSQL() {
+  const propsPath = path.join(appRoot, 'ios', 'Podfile.properties.json');
+  if (!fs.existsSync(propsPath)) {
+    return false;
+  }
+  try {
+    const props = JSON.parse(fs.readFileSync(propsPath, 'utf8'));
+    return props['expo.sqlite.useLibSQL'] === 'true';
+  } catch {
+    return false;
+  }
+}
+
+function main() {
+  if (!fs.existsSync(pkgRoot)) {
+    return;
+  }
+  if (readUseLibSQL()) {
+    return;
+  }
+
+  const vendorDir = path.join(pkgRoot, 'vendor', 'sqlite3');
+  const iosDir = path.join(pkgRoot, 'ios');
+  for (const file of ['sqlite3.c', 'sqlite3.h']) {
+    const src = path.join(vendorDir, file);
+    const dest = path.join(iosDir, file);
+    if (!fs.existsSync(src)) {
+      console.warn(`[ensure-expo-sqlite-ios] missing vendor file: ${src}`);
+      continue;
+    }
+    if (fs.existsSync(dest)) {
+      continue;
+    }
+    fs.mkdirSync(iosDir, { recursive: true });
+    fs.copyFileSync(src, dest);
+    console.log(`[ensure-expo-sqlite-ios] copied ${file} -> ios/`);
+  }
+}
+
+main();

app-expo/scripts/ios-prebuild.sh

@@ -47,6 +47,10 @@ done
 echo "==> expo prebuild --platform ios --clean"
 npx expo prebuild --platform ios --clean
 
+echo "==> ensure expo-sqlite native sources + pod install"
+node scripts/ensure-expo-sqlite-ios.js
+(cd ios && pod install)
+
 shopt -s nullglob
 WORKSPACES=(ios/*.xcworkspace)
 shopt -u nullglob

app-expo/src/features/voice/recorder.ts

@@ -18,8 +18,8 @@ type StatusListener = (status: RecorderStatus) => void;
 type RecordingCompleteListener = (uri: string, durationMs: number) => void;
 
 /**
- * Tencent SentenceRecognition is currently called with `EngSerViceType=16k_zh`
- * and `VoiceFormat=m4a`, so record speech in that shape directly instead of
+ * Tencent SentenceRecognition uses `EngSerViceType=16k_zh_large` and
+ * `VoiceFormat=m4a`, so record speech in that shape directly instead of
  * relying on Expo's default 44.1 kHz stereo preset.
  */
 export const VOICE_RECORDING_OPTIONS: RecordingOptions = {

app-expo/tests/features/voice/recorder.test.ts

@@ -18,7 +18,7 @@ import {
 } from '@/features/voice/recorder';
 
 describe('buildVoiceRecordingOptions', () => {
-  test('uses 16 kHz mono m4a recording options for Tencent-compatible speech capture', () => {
+  test('uses 16 kHz mono m4a recording options for Tencent 16k_zh_large capture', () => {
     const passedOptions = buildVoiceRecordingOptions();
 
     expect(passedOptions).toEqual(