feat(mirror): support GitHub PAT for private repo mirroring

Accept optional github_token in POST /api/mirror and inject it into
the git clone URL so private repos can be cloned without interactive auth.

Made-with: Cursor

src/server.ts

@@ -97,10 +97,11 @@ app.get('/health', (_req: Request, res: Response) => {
 // ---------------------------------------------------------------------------
 
 app.post('/api/mirror', async (req: Request, res: Response) => {
-    const { github_url, gitea_repo, project_name } = req.body as {
+    const { github_url, gitea_repo, project_name, github_token } = req.body as {
         github_url?: string;
         gitea_repo?: string;  // e.g. "mark/opsos"
         project_name?: string;
+        github_token?: string; // PAT for private repos
     };
 
     if (!github_url || !gitea_repo) {
@@ -132,8 +133,14 @@ app.post('/api/mirror', async (req: Request, res: Response) => {
         console.log(`[mirror] Cloning ${github_url} → ${tmpDir}`);
         fs.mkdirSync(tmpDir, { recursive: true });
 
+        // Build authenticated clone URL for private repos
+        let cloneUrl = github_url;
+        if (github_token) {
+            cloneUrl = github_url.replace('https://', `https://${github_token}@`);
+        }
+
         // Mirror-clone the GitHub repo (preserves all branches + tags)
-        execSync(`git clone --mirror "${github_url}" "${tmpDir}/.git"`, {
+        execSync(`git clone --mirror "${cloneUrl}" "${tmpDir}/.git"`, {
             stdio: 'pipe',
             timeout: 120_000
         });