fix: Improve microphone permission handling and audio capture robustness

- Add device enumeration check before attempting to capture audio
- Use simpler audio constraints (audio: true) instead of specific options
- Add fallback to explicit device ID if simple constraints fail
- Add more descriptive error messages for different failure modes
- Enhance Electron permission handlers with better logging
- Add setDevicePermissionHandler for audio device access
- Include 'microphone' in allowed permissions list

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

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

client/src/pages/meeting-detail.html

@@ -405,9 +405,26 @@
           return;
         }
 
-        mediaStream = await navigator.mediaDevices.getUserMedia({
-          audio: { echoCancellation: true, noiseSuppression: true }
-        });
+        // Check for available audio devices first
+        const devices = await navigator.mediaDevices.enumerateDevices();
+        const audioInputs = devices.filter(d => d.kind === 'audioinput');
+        console.log('Available audio inputs:', audioInputs.length, audioInputs);
+
+        if (audioInputs.length === 0) {
+          alert('No microphone found. Please connect a microphone and try again.');
+          return;
+        }
+
+        // Try with simple constraints first, fall back to more specific ones
+        try {
+          mediaStream = await navigator.mediaDevices.getUserMedia({ audio: true });
+        } catch (simpleErr) {
+          console.warn('Simple audio constraints failed, trying with device ID:', simpleErr);
+          // Try with explicit device ID
+          mediaStream = await navigator.mediaDevices.getUserMedia({
+            audio: { deviceId: audioInputs[0].deviceId }
+          });
+        }
 
         isRecording = true;
         recordBtn.textContent = 'Stop Recording';
@@ -422,7 +439,15 @@
 
       } catch (error) {
         console.error('Start recording error:', error);
-        alert('Error starting recording: ' + error.message);
+        let errorMsg = 'Error starting recording: ' + error.message;
+        if (error.name === 'NotAllowedError') {
+          errorMsg = 'Microphone access denied. Please grant permission and try again.';
+        } else if (error.name === 'NotFoundError') {
+          errorMsg = 'No microphone found. Please connect a microphone and try again.';
+        } else if (error.name === 'NotReadableError') {
+          errorMsg = 'Microphone is in use by another application. Please close other apps using the microphone.';
+        }
+        alert(errorMsg);
         await cleanupRecording();
       }
     }