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>

utils/paths.js

@@ -14,24 +14,104 @@ class LuantiPaths {
     await appConfig.load();
     const configuredDataDir = appConfig.getDataDirectory();
     this.setDataDirectory(configuredDataDir);
+    console.log(`Paths initialized with data directory: ${configuredDataDir}`);
+  }
+
+  async forceReload() {
+    // Force reload the app config and reinitialize paths
+    delete require.cache[require.resolve('./app-config')];
+    const appConfig = require('./app-config');
+    await appConfig.load();
+    const configuredDataDir = appConfig.getDataDirectory();
+    this.setDataDirectory(configuredDataDir);
+    console.log(`Paths force reloaded with data directory: ${configuredDataDir}`);
   }
 
   getDefaultDataDirectory() {
-    // Check for common Luanti data directories
+    const validDirs = this.detectLuantiDataDirectories();
+    return validDirs.length > 0 ? validDirs[0].path : path.join(os.homedir(), '.minetest');
+  }
+
+  detectLuantiDataDirectories() {
     const homeDir = os.homedir();
-    const possibleDirs = [
-      path.join(homeDir, '.luanti'),
-      path.join(homeDir, '.minetest')
+    const candidateDirs = [
+      // Flatpak installations
+      { 
+        path: path.join(homeDir, '.var/app/org.luanti.luanti/.minetest'), 
+        type: 'Flatpak (org.luanti.luanti)',
+        description: 'Luanti installed via Flatpak'
+      },
+      { 
+        path: path.join(homeDir, '.var/app/net.minetest.Minetest/.minetest'), 
+        type: 'Flatpak (net.minetest.Minetest)',
+        description: 'Minetest installed via Flatpak'
+      },
+      // Snap installations (they typically use ~/snap/app-name/current/.local/share/minetest)
+      { 
+        path: path.join(homeDir, 'snap/luanti/current/.local/share/minetest'), 
+        type: 'Snap (luanti)',
+        description: 'Luanti installed via Snap'
+      },
+      { 
+        path: path.join(homeDir, 'snap/minetest/current/.local/share/minetest'), 
+        type: 'Snap (minetest)',
+        description: 'Minetest installed via Snap'
+      },
+      // System package installations
+      { 
+        path: path.join(homeDir, '.luanti'), 
+        type: 'System Package',
+        description: 'System-wide Luanti installation'
+      },
+      { 
+        path: path.join(homeDir, '.minetest'), 
+        type: 'System Package',
+        description: 'System-wide Minetest installation'
+      },
+      // AppImage or manual installations might use these
+      { 
+        path: path.join(homeDir, '.local/share/minetest'), 
+        type: 'User Installation',
+        description: 'User-local installation'
+      }
     ];
 
-    // Use the first one that exists, or default to .minetest
-    for (const dir of possibleDirs) {
-      if (fs.existsSync(dir)) {
-        return dir;
+    // Check which directories exist and contain expected Luanti files
+    const validDirs = [];
+    for (const candidate of candidateDirs) {
+      if (fs.existsSync(candidate.path)) {
+        // Check if it looks like a valid Luanti data directory
+        const hasConfig = fs.existsSync(path.join(candidate.path, 'minetest.conf'));
+        const hasWorlds = fs.existsSync(path.join(candidate.path, 'worlds'));
+        const hasDebug = fs.existsSync(path.join(candidate.path, 'debug.txt'));
+        
+        // Even if some files don't exist, the directory might be valid if it exists
+        // (Luanti creates files on first run)
+        candidate.confidence = (hasConfig ? 1 : 0) + (hasWorlds ? 1 : 0) + (hasDebug ? 0.5 : 0);
+        candidate.exists = true;
+        candidate.hasConfig = hasConfig;
+        candidate.hasWorlds = hasWorlds;
+        candidate.hasDebug = hasDebug;
+        
+        validDirs.push(candidate);
       }
     }
+
+    // Sort by confidence (directories with more Luanti files first)
+    validDirs.sort((a, b) => b.confidence - a.confidence);
     
-    return path.join(homeDir, '.minetest');
+    return validDirs;
+  }
+
+  async getGameDisplayName(gameId) {
+    try {
+      const games = await this.getInstalledGames();
+      const game = games.find(g => g.name === gameId);
+      return game ? game.title : gameId;
+    } catch (error) {
+      console.error('Error getting game display name:', error);
+      return gameId;
+    }
   }
 
   setDataDirectory(dataDir) {
@@ -113,12 +193,11 @@ class LuantiPaths {
 
   async getInstalledGames() {
     const games = [];
+    // For Flatpak and other sandboxed installations, only look in the configured data directory
+    // System installations might also have access to additional directories, but we should
+    // primarily focus on the configured data directory to match what Luanti actually sees
     const possibleGameDirs = [
-      this.gamesDir, // User games directory
-      '/usr/share/luanti/games', // System games directory
-      '/usr/share/minetest/games', // Legacy system games directory
-      path.join(process.env.HOME || '/root', '.minetest/games'), // Explicit user path
-      path.join(process.env.HOME || '/root', '.luanti/games') // New user path
+      this.gamesDir // Only the configured games directory
     ];
 
     for (const gameDir of possibleGameDirs) {