feat(editor): Change Code Editor to show diffs in source control panel and during messaging.

Add merge view and minimap extensions to CodeMirror for enhanced code
editing capabilities. Increase Express JSON and URL-encoded payload
limits from default (100kb) to 50mb to support larger file operations
and git diffs.

server/index.js

@@ -172,7 +172,8 @@ const wss = new WebSocketServer({
 app.locals.wss = wss;
 
 app.use(cors());
-app.use(express.json());
+app.use(express.json({ limit: '50mb' }));
+app.use(express.urlencoded({ limit: '50mb', extended: true }));
 
 // Optional API key validation (if configured)
 app.use('/api', validateApiKey);
@@ -408,7 +409,10 @@ app.get('/api/projects/:projectName/file', authenticateToken, async (req, res) =
             return res.status(404).json({ error: 'Project not found' });
         }
 
-        const resolved = path.resolve(filePath);
+        // Handle both absolute and relative paths
+        const resolved = path.isAbsolute(filePath)
+            ? path.resolve(filePath)
+            : path.resolve(projectRoot, filePath);
         const normalizedRoot = path.resolve(projectRoot) + path.sep;
         if (!resolved.startsWith(normalizedRoot)) {
             return res.status(403).json({ error: 'Path must be under project root' });
@@ -504,21 +508,15 @@ app.put('/api/projects/:projectName/file', authenticateToken, async (req, res) =
             return res.status(404).json({ error: 'Project not found' });
         }
 
-        const resolved = path.resolve(filePath);
+        // Handle both absolute and relative paths
+        const resolved = path.isAbsolute(filePath)
+            ? path.resolve(filePath)
+            : path.resolve(projectRoot, filePath);
         const normalizedRoot = path.resolve(projectRoot) + path.sep;
         if (!resolved.startsWith(normalizedRoot)) {
             return res.status(403).json({ error: 'Path must be under project root' });
         }
 
-        // Create backup of original file
-        try {
-            const backupPath = resolved + '.backup.' + Date.now();
-            await fsPromises.copyFile(resolved, backupPath);
-            console.log('📋 Created backup:', backupPath);
-        } catch (backupError) {
-            console.warn('Could not create backup:', backupError.message);
-        }
-
         // Write the new content
         await fsPromises.writeFile(resolved, content, 'utf8');
 

server/routes/git.js

@@ -21,6 +21,35 @@ async function getActualProjectPath(projectName) {
   }
 }
 
+// Helper function to strip git diff headers
+function stripDiffHeaders(diff) {
+  if (!diff) return '';
+
+  const lines = diff.split('\n');
+  const filteredLines = [];
+  let startIncluding = false;
+
+  for (const line of lines) {
+    // Skip all header lines including diff --git, index, file mode, and --- / +++ file paths
+    if (line.startsWith('diff --git') ||
+        line.startsWith('index ') ||
+        line.startsWith('new file mode') ||
+        line.startsWith('deleted file mode') ||
+        line.startsWith('---') ||
+        line.startsWith('+++')) {
+      continue;
+    }
+
+    // Start including lines from @@ hunk headers onwards
+    if (line.startsWith('@@') || startIncluding) {
+      startIncluding = true;
+      filteredLines.push(line);
+    }
+  }
+
+  return filteredLines.join('\n');
+}
+
 // Helper function to validate git repository
 async function validateGitRepository(projectPath) {
   try {
@@ -124,32 +153,39 @@ router.get('/diff', async (req, res) => {
     // Validate git repository
     await validateGitRepository(projectPath);
     
-    // Check if file is untracked
+    // Check if file is untracked or deleted
     const { stdout: statusOutput } = await execAsync(`git status --porcelain "${file}"`, { cwd: projectPath });
     const isUntracked = statusOutput.startsWith('??');
-    
+    const isDeleted = statusOutput.trim().startsWith('D ') || statusOutput.trim().startsWith(' D');
+
     let diff;
     if (isUntracked) {
       // For untracked files, show the entire file content as additions
       const fileContent = await fs.readFile(path.join(projectPath, file), 'utf-8');
       const lines = fileContent.split('\n');
-      diff = `--- /dev/null\n+++ b/${file}\n@@ -0,0 +1,${lines.length} @@\n` + 
+      diff = `--- /dev/null\n+++ b/${file}\n@@ -0,0 +1,${lines.length} @@\n` +
              lines.map(line => `+${line}`).join('\n');
+    } else if (isDeleted) {
+      // For deleted files, show the entire file content from HEAD as deletions
+      const { stdout: fileContent } = await execAsync(`git show HEAD:"${file}"`, { cwd: projectPath });
+      const lines = fileContent.split('\n');
+      diff = `--- a/${file}\n+++ /dev/null\n@@ -1,${lines.length} +0,0 @@\n` +
+             lines.map(line => `-${line}`).join('\n');
     } else {
       // Get diff for tracked files
       // First check for unstaged changes (working tree vs index)
       const { stdout: unstagedDiff } = await execAsync(`git diff -- "${file}"`, { cwd: projectPath });
-      
+
       if (unstagedDiff) {
         // Show unstaged changes if they exist
-        diff = unstagedDiff;
+        diff = stripDiffHeaders(unstagedDiff);
       } else {
         // If no unstaged changes, check for staged changes (index vs HEAD)
         const { stdout: stagedDiff } = await execAsync(`git diff --cached -- "${file}"`, { cwd: projectPath });
-        diff = stagedDiff || '';
+        diff = stripDiffHeaders(stagedDiff) || '';
       }
     }
-    
+
     res.json({ diff });
   } catch (error) {
     console.error('Git diff error:', error);
@@ -157,6 +193,61 @@ router.get('/diff', async (req, res) => {
   }
 });
 
+// Get file content with diff information for CodeEditor
+router.get('/file-with-diff', async (req, res) => {
+  const { project, file } = req.query;
+
+  if (!project || !file) {
+    return res.status(400).json({ error: 'Project name and file path are required' });
+  }
+
+  try {
+    const projectPath = await getActualProjectPath(project);
+
+    // Validate git repository
+    await validateGitRepository(projectPath);
+
+    // Check file status
+    const { stdout: statusOutput } = await execAsync(`git status --porcelain "${file}"`, { cwd: projectPath });
+    const isUntracked = statusOutput.startsWith('??');
+    const isDeleted = statusOutput.trim().startsWith('D ') || statusOutput.trim().startsWith(' D');
+
+    let currentContent = '';
+    let oldContent = '';
+
+    if (isDeleted) {
+      // For deleted files, get content from HEAD
+      const { stdout: headContent } = await execAsync(`git show HEAD:"${file}"`, { cwd: projectPath });
+      oldContent = headContent;
+      currentContent = headContent; // Show the deleted content in editor
+    } else {
+      // Get current file content
+      currentContent = await fs.readFile(path.join(projectPath, file), 'utf-8');
+
+      if (!isUntracked) {
+        // Get the old content from HEAD for tracked files
+        try {
+          const { stdout: headContent } = await execAsync(`git show HEAD:"${file}"`, { cwd: projectPath });
+          oldContent = headContent;
+        } catch (error) {
+          // File might be newly added to git (staged but not committed)
+          oldContent = '';
+        }
+      }
+    }
+
+    res.json({
+      currentContent,
+      oldContent,
+      isDeleted,
+      isUntracked
+    });
+  } catch (error) {
+    console.error('Git file-with-diff error:', error);
+    res.json({ error: error.message });
+  }
+});
+
 // Commit changes
 router.post('/commit', async (req, res) => {
   const { project, message, files } = req.body;