feat(speech): enhance speech configuration and example integration

- Add comprehensive speech configuration in .env.example and app config
- Update Docker speech Dockerfile for more flexible model handling
- Create detailed README for speech-to-text examples
- Implement example script demonstrating speech features
- Improve speech service initialization and configuration management

examples/speech-to-text-example.ts

@@ -0,0 +1,91 @@
+import { SpeechToText, TranscriptionResult, WakeWordEvent } from '../src/speech/speechToText';
+import path from 'path';
+
+async function main() {
+    // Initialize the speech-to-text service
+    const speech = new SpeechToText('fast-whisper');
+
+    // Check if the service is available
+    const isHealthy = await speech.checkHealth();
+    if (!isHealthy) {
+        console.error('Speech service is not available. Make sure Docker is running and the fast-whisper container is up.');
+        console.error('Run: docker-compose up -d');
+        process.exit(1);
+    }
+
+    console.log('Speech service is ready!');
+    console.log('Listening for wake words: "hey jarvis", "ok google", "alexa"');
+    console.log('Press Ctrl+C to exit');
+
+    // Set up event handlers
+    speech.on('wake_word', (event: WakeWordEvent) => {
+        console.log('\n🎤 Wake word detected!');
+        console.log('  Timestamp:', event.timestamp);
+        console.log('  Audio file:', event.audioFile);
+        console.log('  Metadata file:', event.metadataFile);
+    });
+
+    speech.on('transcription', (event: { audioFile: string; result: TranscriptionResult }) => {
+        console.log('\n📝 Transcription result:');
+        console.log('  Full text:', event.result.text);
+        console.log('\n  Segments:');
+        event.result.segments.forEach((segment, index) => {
+            console.log(`    ${index + 1}. [${segment.start.toFixed(2)}s - ${segment.end.toFixed(2)}s] (${(segment.confidence * 100).toFixed(1)}% confidence)`);
+            console.log(`       "${segment.text}"`);
+        });
+    });
+
+    speech.on('progress', (event: { type: string; data: string }) => {
+        if (event.type === 'stderr' && !event.data.includes('Loading model')) {
+            console.error('❌ Error:', event.data);
+        }
+    });
+
+    speech.on('error', (error: Error) => {
+        console.error('❌ Error:', error.message);
+    });
+
+    // Example of manual transcription
+    async function transcribeFile(filepath: string) {
+        try {
+            console.log(`\n🎯 Manually transcribing: ${filepath}`);
+            const result = await speech.transcribeAudio(filepath, {
+                model: 'base.en',  // You can change this to tiny.en, small.en, medium.en, or large-v2
+                language: 'en',
+                temperature: 0,
+                beamSize: 5
+            });
+
+            console.log('\n📝 Transcription result:');
+            console.log('  Text:', result.text);
+        } catch (error) {
+            console.error('❌ Transcription failed:', error instanceof Error ? error.message : error);
+        }
+    }
+
+    // Create audio directory if it doesn't exist
+    const audioDir = path.join(__dirname, '..', 'audio');
+    if (!require('fs').existsSync(audioDir)) {
+        require('fs').mkdirSync(audioDir, { recursive: true });
+    }
+
+    // Start wake word detection
+    speech.startWakeWordDetection(audioDir);
+
+    // Example: You can also manually transcribe files
+    // Uncomment the following line and replace with your audio file:
+    // await transcribeFile('/path/to/your/audio.wav');
+
+    // Keep the process running
+    process.on('SIGINT', () => {
+        console.log('\nStopping speech service...');
+        speech.stopWakeWordDetection();
+        process.exit(0);
+    });
+}
+
+// Run the example
+main().catch(error => {
+    console.error('Fatal error:', error);
+    process.exit(1);
+});