Add iOS Safari support for voice commands with MediaRecorder fallback

Frontend changes:
- Add MediaRecorder fallback for iOS Safari (no Web Speech API support)
- Automatically detect browser capabilities and use appropriate method
- Add usesFallback flag to track which method is being used
- Update UI to show "Recording..." vs "Listening..." based on method
- Add iOS-specific indicator text
- Handle microphone permissions and errors properly

Backend changes:
- Update /api/v1/voice/transcribe to accept both audio files and text
- Support text-based classification (from Web Speech API)
- Support audio file transcription + classification (from MediaRecorder)
- Return unified response format with transcript and classification

How it works:
- Chrome/Edge: Uses Web Speech API for realtime transcription
- iOS Safari: Records audio with MediaRecorder, sends to server for transcription
- Fallback is transparent to the user with appropriate UI feedback

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

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

maternal-app/maternal-app-backend/src/modules/voice/voice.controller.ts

@@ -18,20 +18,46 @@ export class VoiceController {
   @UseInterceptors(FileInterceptor('audio'))
   async transcribeAudio(
     @UploadedFile() file: Express.Multer.File,
+    @Body('text') text?: string,
     @Body('language') language?: string,
+    @Body('childName') childName?: string,
   ) {
-    if (!file) {
-      throw new BadRequestException('Audio file is required');
+    // If text is provided (from Web Speech API), classify it directly
+    if (text) {
+      const result = await this.voiceService.extractActivityFromText(
+        text,
+        language || 'en',
+        childName,
+      );
+
+      return {
+        success: true,
+        transcript: text,
+        classification: result,
+      };
     }
 
-    const result = await this.voiceService.transcribeAudio(
+    // Otherwise, transcribe the audio file
+    if (!file) {
+      throw new BadRequestException('Audio file or text is required');
+    }
+
+    const transcription = await this.voiceService.transcribeAudio(
       file.buffer,
       language,
     );
 
+    // Also classify the transcription
+    const classification = await this.voiceService.extractActivityFromText(
+      transcription.text,
+      language || 'en',
+      childName,
+    );
+
     return {
       success: true,
-      data: result,
+      transcript: transcription.text,
+      classification: classification,
     };
   }