Fix server management issues and improve overall stability

Major server management fixes:
- Replace Flatpak-specific pkill with universal process tree termination using pstree + process.kill()
- Fix signal format errors (SIGTERM/SIGKILL instead of TERM/KILL strings)
- Add 5-second cooldown after server stop to prevent race conditions with external detection
- Enable Stop Server button for external servers in UI
- Implement proper timeout handling with process tree killing

ContentDB improvements:
- Fix download retry logic and "closed" error by preventing concurrent zip extraction
- Implement smart root directory detection and stripping during package extraction
- Add game-specific timeout handling (8s for VoxeLibre vs 3s for simple games)

World creation fixes:
- Make world creation asynchronous to prevent browser hangs
- Add WebSocket notifications for world creation completion status

Other improvements:
- Remove excessive debug logging
- Improve error handling and user feedback throughout the application
- Clean up temporary files and unnecessary logging

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

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

routes/extensions.js

@@ -12,12 +12,14 @@ const router = express.Router();
 const contentdb = new ContentDBClient();
 const packageRegistry = new PackageRegistry();
 
-// Initialize package registry
+// Initialize package registry - will be reinitialized when paths change
 packageRegistry.init().catch(console.error);
 
 // Main Extensions page - shows installed content and installer
 router.get('/', async (req, res) => {
   try {
+    // Ensure we're using the current data directory
+    await paths.initialize();
     paths.ensureDirectories();
     
     // Get installed packages from registry (games, mods, texture packs)