Fix Electron Forge packaging error on macOS

Remove extraResource configuration that was trying to copy non-existent
dist/assets directory. The Vite plugin handles all assets automatically.

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

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

forge.config.js

@@ -1,11 +1,6 @@
-const path = require('path');
-
 module.exports = {
   packagerConfig: {
     asar: true,
-    extraResource: [
-      path.join(__dirname, 'dist', 'assets'),
-    ],
   },
   rebuildConfig: {},
   makers: [