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>

views/auth/register.ejs

@@ -67,6 +67,53 @@ const body = `
                 </div>
             </div>
             
+            ${isFirstUser ? `
+                <div class="form-group" style="margin-top: 2rem;">
+                    <label for="dataDirectory">Luanti Data Directory*</label>
+                    <select id="dataDirectory" name="dataDirectory" class="form-control" required>
+                        ${detectedDirectories.length > 0 ? 
+                            detectedDirectories.map(dir => `
+                                <option value="${dir.path}" 
+                                        ${dir.path === defaultDataDir ? 'selected' : ''}
+                                        data-confidence="${dir.confidence}">
+                                    ${dir.type}: ${dir.path}
+                                    ${dir.hasConfig ? ' ✓ Config' : ''}
+                                    ${dir.hasWorlds ? ' ✓ Worlds' : ''}
+                                    ${dir.hasDebug ? ' ✓ Active' : ''}
+                                </option>
+                            `).join('') :
+                            `<option value="${defaultDataDir}">${defaultDataDir} (Default)</option>`
+                        }
+                        <option value="custom">Custom directory...</option>
+                    </select>
+                    <small style="color: var(--text-secondary);">
+                        Choose the correct Luanti data directory based on your installation method. 
+                        Directories with ✓ marks have existing Luanti files.
+                    </small>
+                    
+                    <div id="customDirGroup" style="display: none; margin-top: 1rem;">
+                        <label for="customDataDirectory">Custom Directory Path</label>
+                        <input type="text" 
+                               id="customDataDirectory" 
+                               name="customDataDirectory" 
+                               class="form-control" 
+                               placeholder="/path/to/luanti/data/directory">
+                        <small style="color: var(--text-secondary);">Enter the full path to your Luanti data directory</small>
+                    </div>
+                </div>
+                
+                <div class="alert alert-warning">
+                    <h4 style="margin-top: 0;">⚠️ Important: Data Directory Selection</h4>
+                    <p>The data directory must match where your Luanti installation stores its data:</p>
+                    <ul style="margin: 0.5rem 0;">
+                        <li><strong>Flatpak:</strong> ~/.var/app/org.luanti.luanti/.minetest</li>
+                        <li><strong>System Package:</strong> ~/.minetest or ~/.luanti</li>
+                        <li><strong>Snap:</strong> ~/snap/luanti/current/.local/share/minetest</li>
+                    </ul>
+                    <p style="margin-bottom: 0;">Choosing the wrong directory will prevent the web interface from managing your worlds and server properly.</p>
+                </div>
+            ` : ''}
+            
             <div style="display: flex; justify-content: space-between; align-items: center; margin-top: 2rem;">
                 <a href="/login" class="btn btn-outline">
                     Already have an account?
@@ -109,6 +156,24 @@ document.getElementById('password').addEventListener('input', function() {
         confirmPassword.dispatchEvent(new Event('input'));
     }
 });
+
+// Handle custom data directory selection
+const dataDirectorySelect = document.getElementById('dataDirectory');
+const customDirGroup = document.getElementById('customDirGroup');
+const customDirInput = document.getElementById('customDataDirectory');
+
+if (dataDirectorySelect && customDirGroup) {
+    dataDirectorySelect.addEventListener('change', function() {
+        if (this.value === 'custom') {
+            customDirGroup.style.display = 'block';
+            customDirInput.required = true;
+        } else {
+            customDirGroup.style.display = 'none';
+            customDirInput.required = false;
+            customDirInput.value = '';
+        }
+    });
+}
 </script>
 `;
 %>