feat(updates): add system update endpoint and UI

Add automatic update functionality to allow users to update the
application directly from the UI without manual git commands.

Changes:
- Add POST /api/system/update endpoint that runs git pull and npm
  install
- Enhance useVersionCheck hook to fetch release information including
  changelog
- Update VersionUpgradeModal to display changelog and handle one-click
  updates
- Add update progress tracking with output display and error handling
- Bump version to 1.10.4

The update endpoint executes git checkout main, git pull, and npm
install, providing real-time output to the user. After successful
update, users are prompted to restart the server.

server/index.js

@@ -237,6 +237,71 @@ app.get('/api/config', authenticateToken, (req, res) => {
     });
 });
 
+// System update endpoint
+app.post('/api/system/update', authenticateToken, async (req, res) => {
+    try {
+        // Get the project root directory (parent of server directory)
+        const projectRoot = path.join(__dirname, '..');
+
+        console.log('Starting system update from directory:', projectRoot);
+
+        // Run the update command
+        const updateCommand = 'git checkout main && git pull && npm install';
+
+        const child = spawn('sh', ['-c', updateCommand], {
+            cwd: projectRoot,
+            env: process.env
+        });
+
+        let output = '';
+        let errorOutput = '';
+
+        child.stdout.on('data', (data) => {
+            const text = data.toString();
+            output += text;
+            console.log('Update output:', text);
+        });
+
+        child.stderr.on('data', (data) => {
+            const text = data.toString();
+            errorOutput += text;
+            console.error('Update error:', text);
+        });
+
+        child.on('close', (code) => {
+            if (code === 0) {
+                res.json({
+                    success: true,
+                    output: output || 'Update completed successfully',
+                    message: 'Update completed. Please restart the server to apply changes.'
+                });
+            } else {
+                res.status(500).json({
+                    success: false,
+                    error: 'Update command failed',
+                    output: output,
+                    errorOutput: errorOutput
+                });
+            }
+        });
+
+        child.on('error', (error) => {
+            console.error('Update process error:', error);
+            res.status(500).json({
+                success: false,
+                error: error.message
+            });
+        });
+
+    } catch (error) {
+        console.error('System update error:', error);
+        res.status(500).json({
+            success: false,
+            error: error.message
+        });
+    }
+});
+
 app.get('/api/projects', authenticateToken, async (req, res) => {
     try {
         const projects = await getProjects();