fix: adress pr comments

- Added validation to check if the specified worktree path exists before generating commit messages.
- Implemented a check to ensure the worktree path is a valid git repository by verifying the presence of the .git directory.
- Improved error handling by returning appropriate responses for invalid paths and non-git repositories.

apps/server/src/routes/worktree/routes/generate-commit-message.ts

@@ -8,6 +8,8 @@
 import type { Request, Response } from 'express';
 import { exec } from 'child_process';
 import { promisify } from 'util';
+import { existsSync } from 'fs';
+import { join } from 'path';
 import { query } from '@anthropic-ai/claude-agent-sdk';
 import { createLogger } from '@automaker/utils';
 import { DEFAULT_PHASE_MODELS, isCursorModel, stripProviderPrefix } from '@automaker/types';
@@ -87,6 +89,27 @@ export function createGenerateCommitMessageHandler(
         return;
       }
 
+      // Validate that the directory exists
+      if (!existsSync(worktreePath)) {
+        const response: GenerateCommitMessageErrorResponse = {
+          success: false,
+          error: 'worktreePath does not exist',
+        };
+        res.status(400).json(response);
+        return;
+      }
+
+      // Validate that it's a git repository (check for .git folder or file for worktrees)
+      const gitPath = join(worktreePath, '.git');
+      if (!existsSync(gitPath)) {
+        const response: GenerateCommitMessageErrorResponse = {
+          success: false,
+          error: 'worktreePath is not a git repository',
+        };
+        res.status(400).json(response);
+        return;
+      }
+
       logger.info(`Generating commit message for worktree: ${worktreePath}`);
 
       // Get git diff of staged and unstaged changes