feat(git): inline file diffs in commit history rows (#1291)

* chore: add .worktrees/ to gitignore for worktree workflow

* feat(git): add getCommitFileDiff service function

* docs(git): document getCommitFileDiff in module docs

* feat(git): add GET /api/git/commit-file-diff route

* feat(git): add CommitFileDiffResponse type and GitAPI method signature

* feat(git): add getCommitFileDiff HTTP client function

* feat(git): add getCommitFileDiff API facade

* feat(git): add getCommitFileDiff stub to VS Code bridge

* feat(git): add getCommitFileDiff to VS Code gitService and bridge handler

* feat(git): add inline file diff to history commit rows

* fix(git): consolidate CommitFileDiffResponse import to gitApi facade

* fix(git): pass directory through history, validate hash, propagate git errors

* fix(git): use exit code check for VS Code getCommitFileDiff error detection

* fix(git): VS Code rename detection, hash validation parity, retry on error

* fix(git): register scroll container as virtualizer root to fix empty space in history diffs

* fix(git): address greptile review — rename key extraction, directory guard, language detection, isBinary cleanup

* fix(git): harden history inline diffs

---------

Co-authored-by: Bohdan Triapitsyn <artmore@protonmail.com>

packages/vscode/src/gitService.ts

@@ -279,6 +279,27 @@ async function execGit(args: string[], cwd: string): Promise<{ stdout: string; s
   });
 }
 
+function extractGitStatusPath(status: string, pathPart: string): string {
+  if ((status === 'R' || status === 'C') && pathPart.includes('\t')) {
+    return pathPart.split('\t').pop() || pathPart;
+  }
+  return pathPart;
+}
+
+function extractGitNumstatDestinationPath(filePath: string): string {
+  if (!filePath.includes(' => ')) {
+    return filePath;
+  }
+
+  const braceMatch = filePath.match(/^(.*)\{([^{}]*)\s=>\s([^{}]*)\}(.*)$/);
+  if (braceMatch) {
+    const [, prefix, , destination, suffix] = braceMatch;
+    return `${prefix}${destination}${suffix}`.replace(/\/+/g, '/');
+  }
+
+  return filePath.split(' => ').pop()?.trim() || filePath;
+}
+
 // ============== Repository Operations ==============
 
 /**
@@ -2631,31 +2652,84 @@ export async function getCommitFiles(
   directory: string,
   hash: string
 ): Promise<{ files: Array<{ path: string; insertions: number; deletions: number; isBinary: boolean; changeType: string }> }> {
-  const result = await execGit(['show', '--numstat', '--format=', hash], directory);
-  
-  if (result.exitCode !== 0) {
+  const numstatResult = await execGit(['show', '--numstat', '--format=', hash], directory);
+
+  if (numstatResult.exitCode !== 0) {
     return { files: [] };
   }
 
   const files: Array<{ path: string; insertions: number; deletions: number; isBinary: boolean; changeType: string }> = [];
-  
-  for (const line of result.stdout.trim().split('\n').filter(Boolean)) {
+  const lines = numstatResult.stdout.trim().split('\n').filter(Boolean);
+
+  for (const line of lines) {
     const parts = line.split('\t');
-    if (parts.length >= 3) {
-      const isBinary = parts[0] === '-' && parts[1] === '-';
-      files.push({
-        path: parts[2] || '',
-        insertions: isBinary ? 0 : parseInt(parts[0] || '0', 10),
-        deletions: isBinary ? 0 : parseInt(parts[1] || '0', 10),
-        isBinary,
-        changeType: 'M', // Would need additional parsing for actual change type
-      });
+    if (parts.length < 3) continue;
+
+    const [insertionsRaw, deletionsRaw, ...pathParts] = parts;
+    const filePath = pathParts.join('\t');
+    if (!filePath) continue;
+
+    const isBinary = insertionsRaw === '-' && deletionsRaw === '-';
+    const insertions = isBinary ? 0 : (parseInt(insertionsRaw, 10) || 0);
+    const deletions = isBinary ? 0 : (parseInt(deletionsRaw, 10) || 0);
+
+    let changeType = 'M';
+    if (filePath.includes(' => ')) {
+      changeType = 'R';
+    }
+
+    files.push({ path: filePath, insertions, deletions, isBinary, changeType });
+  }
+
+  // Get accurate change types from --name-status
+  const nameStatusResult = await execGit(['show', '--name-status', '--format=', hash], directory);
+  if (nameStatusResult.exitCode === 0) {
+    const statusMap = new Map<string, string>();
+    for (const line of nameStatusResult.stdout.trim().split('\n').filter(Boolean)) {
+      const match = line.match(/^([AMDRC])\d*\t(.+)$/);
+      if (match) {
+        const [, status, pathPart] = match;
+        statusMap.set(extractGitStatusPath(status, pathPart), status);
+      }
+    }
+    for (const file of files) {
+      const basePath = extractGitNumstatDestinationPath(file.path);
+      const status = statusMap.get(basePath) ?? statusMap.get(file.path);
+      if (status) {
+        file.changeType = status;
+      }
     }
   }
 
   return { files };
 }
 
+export async function getCommitFileDiff(
+  directory: string,
+  hash: string,
+  filePath: string,
+  isBinary: boolean
+): Promise<{ original: string; modified: string; isBinary: boolean }> {
+  if (isBinary) {
+    return { original: '', modified: '', isBinary: true };
+  }
+
+  const [originalResult, modifiedResult] = await Promise.all([
+    execGit(['show', `${hash}^:${filePath}`], directory),
+    execGit(['show', `${hash}:${filePath}`], directory),
+  ]);
+
+  if (originalResult.exitCode !== 0 && modifiedResult.exitCode !== 0) {
+    throw new Error(`Failed to read file content at commit ${hash}`);
+  }
+
+  return {
+    original: originalResult.exitCode === 0 ? originalResult.stdout : '',
+    modified: modifiedResult.exitCode === 0 ? modifiedResult.stdout : '',
+    isBinary: false,
+  };
+}
+
 // ============== Git Identity Operations ==============
 
 export interface GitIdentitySummary {