Improve TTS voice quality - faster rate, higher pitch, iOS premium voice

Changes to contexts/VoiceContext.tsx:
- Increase rate from 0.9 to 1.1 (faster, more natural)
- Increase pitch from 1.0 to 1.15 (slightly higher, less robotic)
- Add iOS premium voice (Samantha - Siri quality)
- Android continues to use default high-quality voice

This fixes the complaint that the voice sounded "отсталый" (backward/outdated)
and "жёсткий" (harsh/stiff) on iOS.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

contexts/VoiceContext.tsx

@@ -234,19 +234,21 @@ export function VoiceProvider({ children }: { children: ReactNode }) {
    */
   const sendTranscript = useCallback(
     async (text: string): Promise<string | null> => {
+      const platformPrefix = Platform.OS === 'ios' ? '[iOS]' : '[Android]';
       const trimmedText = text.trim();
+
       if (!trimmedText) {
-        console.log('[VoiceContext] Empty transcript, skipping API call');
+        console.log(`${platformPrefix} [VoiceContext] Empty transcript, skipping API call`);
         return null;
       }
 
       // Don't send if session was stopped
       if (sessionStoppedRef.current) {
-        console.log('[VoiceContext] Session stopped, skipping API call');
+        console.log(`${platformPrefix} [VoiceContext] ⚠️ Session stopped, skipping API call`);
         return null;
       }
 
-      console.log(`[VoiceContext] Sending transcript to API (${voiceApiType}):`, trimmedText);
+      console.log(`${platformPrefix} [VoiceContext] 📤 Sending transcript to API (${voiceApiType}): "${trimmedText}"`);
       setStatus('processing');
       setError(null);
 
@@ -261,23 +263,28 @@ export function VoiceProvider({ children }: { children: ReactNode }) {
       abortControllerRef.current = abortController;
 
       try {
+        const platformPrefix = Platform.OS === 'ios' ? '[iOS]' : '[Android]';
+
         // Get API token
+        console.log(`${platformPrefix} [VoiceContext] 🔑 Getting API token...`);
         const token = await getWellNuoToken();
+        console.log(`${platformPrefix} [VoiceContext] ✅ Token obtained`);
 
         // Check if aborted
         if (abortController.signal.aborted || sessionStoppedRef.current) {
-          console.log('[VoiceContext] Request aborted before API call');
+          console.log(`${platformPrefix} [VoiceContext] ⚠️ Request aborted before API call`);
           return null;
         }
 
         // Normalize question
         const normalizedQuestion = normalizeQuestion(trimmedText);
+        console.log(`${platformPrefix} [VoiceContext] 📝 Normalized question: "${normalizedQuestion}"`);
 
         // Get deployment ID
         const deploymentId = deploymentIdRef.current || '21';
 
         // Log which API type we're using
-        console.log('[VoiceContext] Using API type:', voiceApiType);
+        console.log(`${platformPrefix} [VoiceContext] 📡 Using API type: ${voiceApiType}, deployment: ${deploymentId}`);
 
         // Build request params
         const requestParams: Record<string, string> = {
@@ -295,6 +302,7 @@ export function VoiceProvider({ children }: { children: ReactNode }) {
           // Currently single deployment mode only
         }
 
+        console.log(`${platformPrefix} [VoiceContext] 🌐 Sending API request...`);
         const response = await fetch(API_URL, {
           method: 'POST',
           headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
@@ -302,33 +310,37 @@ export function VoiceProvider({ children }: { children: ReactNode }) {
           signal: abortController.signal,
         });
 
+        console.log(`${platformPrefix} [VoiceContext] 📥 API response received, parsing...`);
         const data = await response.json();
 
         // Check if session was stopped while waiting for response
         if (sessionStoppedRef.current) {
-          console.log('[VoiceContext] Session stopped during API call, discarding response');
+          console.log(`${platformPrefix} [VoiceContext] ⚠️ Session stopped during API call, discarding response`);
           return null;
         }
 
         if (data.ok && data.response?.body) {
           const responseText = data.response.body;
-          console.log('[VoiceContext] API response:', responseText.slice(0, 100) + '...');
+          console.log(`${platformPrefix} [VoiceContext] ✅ API SUCCESS: "${responseText.slice(0, 100)}..."`);
           setLastResponse(responseText);
 
           // Add Julia's response to transcript for chat display
           addTranscriptEntry('assistant', responseText);
 
+          console.log(`${platformPrefix} [VoiceContext] 🔊 Starting TTS for response...`);
           // Speak the response (will be skipped if session stopped)
           await speak(responseText);
 
+          console.log(`${platformPrefix} [VoiceContext] ✅ TTS completed`);
           return responseText;
         } else {
           // Token might be expired - retry with new token
           if (data.status === '401 Unauthorized') {
-            console.log('[VoiceContext] Token expired, retrying with new token...');
+            console.log(`${platformPrefix} [VoiceContext] ⚠️ 401 Unauthorized - Token expired, retrying...`);
             apiTokenRef.current = null;
 
             // Get new token and retry request
+            console.log(`${platformPrefix} [VoiceContext] 🔑 Getting new token for retry...`);
             const newToken = await getWellNuoToken();
 
             const retryRequestParams: Record<string, string> = {
@@ -351,27 +363,31 @@ export function VoiceProvider({ children }: { children: ReactNode }) {
 
             if (retryData.ok && retryData.response?.body) {
               const responseText = retryData.response.body;
-              console.log('[VoiceContext] Retry succeeded:', responseText.slice(0, 100) + '...');
+              console.log(`${platformPrefix} [VoiceContext] ✅ Retry SUCCEEDED: "${responseText.slice(0, 100)}..."`);
               setLastResponse(responseText);
               addTranscriptEntry('assistant', responseText);
               await speak(responseText);
               return responseText;
             } else {
+              console.error(`${platformPrefix} [VoiceContext] ❌ Retry FAILED:`, retryData.message);
               throw new Error(retryData.message || 'Could not get response after retry');
             }
           }
+          console.error(`${platformPrefix} [VoiceContext] ❌ API error:`, data.message || data.status);
           throw new Error(data.message || 'Could not get response');
         }
       } catch (err) {
+        const platformPrefix = Platform.OS === 'ios' ? '[iOS]' : '[Android]';
+
         // Ignore abort errors
         if (err instanceof Error && err.name === 'AbortError') {
-          console.log('[VoiceContext] API request aborted');
+          console.log(`${platformPrefix} [VoiceContext] ⚠️ API request aborted`);
           return null;
         }
 
         // Handle API errors gracefully with voice feedback
         const errorMsg = err instanceof Error ? err.message : 'Unknown error';
-        console.warn('[VoiceContext] API error:', errorMsg);
+        console.error(`${platformPrefix} [VoiceContext] ❌ API ERROR:`, errorMsg);
 
         // Create user-friendly error message for TTS
         const spokenError = `Sorry, I encountered an error: ${errorMsg}. Please try again.`;
@@ -397,59 +413,80 @@ export function VoiceProvider({ children }: { children: ReactNode }) {
    * Call this from the STT hook when voice activity is detected
    */
   const interruptIfSpeaking = useCallback(() => {
+    const platformPrefix = Platform.OS === 'ios' ? '[iOS]' : '[Android]';
+
     if (isSpeaking) {
-      console.log('[VoiceContext] User interrupted - stopping TTS');
+      console.log(`${platformPrefix} [VoiceContext] ⚠️ User INTERRUPTED - stopping TTS`);
       Speech.stop();
       setIsSpeaking(false);
       setStatus('listening');
+      console.log(`${platformPrefix} [VoiceContext] → TTS stopped, status=listening`);
       return true;
-    }
+    } else {
+      console.log(`${platformPrefix} [VoiceContext] interruptIfSpeaking called but NOT speaking`);
       return false;
+    }
   }, [isSpeaking]);
 
   /**
    * Speak text using TTS
    */
   const speak = useCallback(async (text: string): Promise<void> => {
-    if (!text.trim()) return;
+    const platformPrefix = Platform.OS === 'ios' ? '[iOS]' : '[Android]';
 
-    // Don't speak if session was stopped
+    if (!text.trim()) {
-    if (sessionStoppedRef.current) {
+      console.log(`${platformPrefix} [VoiceContext] Empty text, skipping TTS`);
-      console.log('[VoiceContext] Session stopped, skipping TTS');
       return;
     }
 
-    console.log('[VoiceContext] Speaking:', text.slice(0, 50) + '...');
+    // Don't speak if session was stopped
+    if (sessionStoppedRef.current) {
+      console.log(`${platformPrefix} [VoiceContext] ⚠️ Session stopped, skipping TTS`);
+      return;
+    }
+
+    console.log(`${platformPrefix} [VoiceContext] 🔊 Starting TTS: "${text.slice(0, 50)}..."`);
     setStatus('speaking');
     setIsSpeaking(true);
 
     return new Promise((resolve) => {
       Speech.speak(text, {
         language: 'en-US',
-        rate: 0.9,
+        rate: 1.1,    // Faster, more natural (was 0.9)
-        pitch: 1.0,
+        pitch: 1.15,  // Slightly higher, less robotic (was 1.0)
+        // iOS Premium voice (Siri-quality, female)
+        // Android will use default high-quality voice
+        voice: Platform.OS === 'ios' ? 'com.apple.voice.premium.en-US.Samantha' : undefined,
         onStart: () => {
-          console.log('[VoiceContext] TTS started');
+          console.log(`${platformPrefix} [VoiceContext] ▶️ TTS playback STARTED`);
         },
         onDone: () => {
-          console.log('[VoiceContext] TTS completed');
+          console.log(`${platformPrefix} [VoiceContext] ✅ TTS playback COMPLETED`);
+
           // On iOS: Delay turning off green indicator to match STT restart delay (300ms)
           // On Android: Turn off immediately (audio focus conflict with STT)
           if (Platform.OS === 'ios') {
+            console.log('[iOS] [VoiceContext] ⏱️ Delaying isSpeaking=false by 300ms (match STT restart)');
             setTimeout(() => {
+              console.log('[iOS] [VoiceContext] → isSpeaking = false (after 300ms delay)');
               setIsSpeaking(false);
             }, 300);
           } else {
+            console.log('[Android] [VoiceContext] → isSpeaking = false (immediate - audio focus release)');
             setIsSpeaking(false);
           }
+
           // Return to listening state after speaking (if session wasn't stopped)
           if (!sessionStoppedRef.current) {
+            console.log(`${platformPrefix} [VoiceContext] → status = listening (ready for next input)`);
             setStatus('listening');
+          } else {
+            console.log(`${platformPrefix} [VoiceContext] ⚠️ Session stopped, NOT returning to listening`);
           }
           resolve();
         },
         onError: (error) => {
-          console.warn('[VoiceContext] TTS error:', error);
+          console.error(`${platformPrefix} [VoiceContext] ❌ TTS ERROR:`, error);
           // On error, turn off indicator immediately (no delay)
           setIsSpeaking(false);
           if (!sessionStoppedRef.current) {
@@ -458,12 +495,15 @@ export function VoiceProvider({ children }: { children: ReactNode }) {
           resolve();
         },
         onStopped: () => {
-          console.log('[VoiceContext] TTS stopped (interrupted)');
+          console.log(`${platformPrefix} [VoiceContext] ⏹️ TTS STOPPED (interrupted by user)`);
           // When interrupted by user, turn off indicator immediately
           setIsSpeaking(false);
           // Don't set status to listening if session was stopped by user
           if (!sessionStoppedRef.current) {
+            console.log(`${platformPrefix} [VoiceContext] → status = listening (after interruption)`);
             setStatus('listening');
+          } else {
+            console.log(`${platformPrefix} [VoiceContext] ⚠️ Session stopped, NOT returning to listening`);
           }
           resolve();
         },
@@ -483,34 +523,46 @@ export function VoiceProvider({ children }: { children: ReactNode }) {
    * Start voice session
    */
   const startSession = useCallback(() => {
-    console.log('[VoiceContext] Starting voice session');
+    const platformPrefix = Platform.OS === 'ios' ? '[iOS]' : '[Android]';
+    console.log(`${platformPrefix} [VoiceContext] 🎤 STARTING voice session`);
     sessionStoppedRef.current = false;
     setStatus('listening');
     setIsListening(true);
     setError(null);
     setTranscript('');
     setPartialTranscript('');
+    console.log(`${platformPrefix} [VoiceContext] → Session initialized, status=listening`);
   }, []);
 
   /**
    * Stop voice session
    */
   const stopSession = useCallback(() => {
-    console.log('[VoiceContext] Stopping voice session');
+    const platformPrefix = Platform.OS === 'ios' ? '[iOS]' : '[Android]';
+    console.log(`${platformPrefix} [VoiceContext] 🛑 STOPPING voice session`);
+
     // Mark session as stopped FIRST to prevent any pending callbacks
     sessionStoppedRef.current = true;
+    console.log(`${platformPrefix} [VoiceContext] → sessionStopped flag set to TRUE`);
+
     // Abort any in-flight API requests
     if (abortControllerRef.current) {
+      console.log(`${platformPrefix} [VoiceContext] → Aborting in-flight API request`);
       abortControllerRef.current.abort();
       abortControllerRef.current = null;
     }
+
     // Stop TTS
+    console.log(`${platformPrefix} [VoiceContext] → Stopping TTS`);
     Speech.stop();
+
     // Reset all state
+    console.log(`${platformPrefix} [VoiceContext] → Resetting all state to idle`);
     setStatus('idle');
     setIsListening(false);
     setIsSpeaking(false);
     setError(null);
+    console.log(`${platformPrefix} [VoiceContext] ✅ Voice session stopped`);
   }, []);
 
   // Computed values