feat(matrix-mana-bot): add voice input support (Phase 1)

- Add VoiceModule and VoiceService for STT integration
- Override handleAudioMessage to process voice notes
- Transcribe audio via mana-stt (Whisper)
- Route transcribed text through CommandRouter
- Add voice configuration and environment variables
- Update help text and documentation

Voice flow:
1. User sends voice note
2. Bot downloads and transcribes audio
3. Shows transcription: 🎤 *"text"*
4. Routes as normal text command
5. Returns text response

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

services/matrix-mana-bot/src/bot/bot.module.ts

@@ -3,9 +3,10 @@ import { MatrixService } from './matrix.service';
 import { CommandRouterService } from './command-router.service';
 import { HandlersModule } from '../handlers/handlers.module';
 import { OrchestrationModule } from '../orchestration/orchestration.module';
+import { VoiceModule } from '../voice/voice.module';
 
 @Module({
-	imports: [forwardRef(() => HandlersModule), forwardRef(() => OrchestrationModule)],
+	imports: [forwardRef(() => HandlersModule), forwardRef(() => OrchestrationModule), VoiceModule],
 	providers: [MatrixService, CommandRouterService],
 	exports: [MatrixService, CommandRouterService],
 })