fix: Add microphone permission handlers for Electron

Added session.setPermissionRequestHandler and setPermissionCheckHandler
to automatically grant media/audio capture permissions. This fixes the
"could not start audio source" error when trying to start recording.

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

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

client/src/main.js

@@ -1,4 +1,4 @@
-const { app, BrowserWindow, ipcMain } = require("electron");
+const { app, BrowserWindow, ipcMain, session } = require("electron");
 const path = require("path");
 const fs = require("fs");
 const { spawn } = require("child_process");
@@ -445,6 +445,24 @@ app.whenReady().then(async () => {
   // Load configuration first
   loadConfig();
 
+  // Grant microphone permission automatically
+  session.defaultSession.setPermissionRequestHandler((webContents, permission, callback) => {
+    const allowedPermissions = ['media', 'mediaKeySystem', 'audioCapture'];
+    if (allowedPermissions.includes(permission)) {
+      console.log(`Granting permission: ${permission}`);
+      callback(true);
+    } else {
+      console.log(`Denying permission: ${permission}`);
+      callback(false);
+    }
+  });
+
+  // Also handle permission check (for some Electron versions)
+  session.defaultSession.setPermissionCheckHandler((webContents, permission) => {
+    const allowedPermissions = ['media', 'mediaKeySystem', 'audioCapture'];
+    return allowedPermissions.includes(permission);
+  });
+
   // Start backend sidecar if embedded mode is enabled
   startBackendSidecar();