fix: run skill git sync as repo owner

backend/api/server.py

@@ -787,14 +787,30 @@ class AgentState:
             repo = config.cwd
             if not (repo / '.git').exists():
                 raise ValueError(f'当前工作目录不是 git 仓库：{repo}')
+            git_prefix: list[str] = []
+            if os.name == 'posix' and hasattr(os, 'geteuid') and os.geteuid() == 0:
+                try:
+                    repo_owner = pwd.getpwuid(repo.stat().st_uid).pw_name
+                except (KeyError, OSError):
+                    repo_owner = ''
+                if repo_owner and repo_owner != 'root':
+                    git_prefix = [
+                        'sudo',
+                        '-H',
+                        '-u',
+                        repo_owner,
+                        'env',
+                        'GIT_TERMINAL_PROMPT=0',
+                    ]
 
             def run_git(args: list[str], *, timeout: int = 60) -> subprocess.CompletedProcess[str]:
                 env = {
                     **os.environ,
                     'GIT_TERMINAL_PROMPT': '0',
                 }
+                command = [*git_prefix, 'git', *args] if git_prefix else ['git', *args]
                 proc = subprocess.run(
-                    ['git', *args],
+                    command,
                     cwd=repo,
                     capture_output=True,
                     text=True,
@@ -803,7 +819,8 @@ class AgentState:
                 )
                 if proc.returncode != 0:
                     detail = (proc.stderr or proc.stdout or '').strip()
-                    raise ValueError(f'git {" ".join(args)} 失败：{detail}')
+                    run_as = f'（以 {git_prefix[3]} 用户执行）' if git_prefix else ''
+                    raise ValueError(f'git {" ".join(args)}{run_as} 失败：{detail}')
                 return proc
 
             dirty = run_git(['status', '--porcelain', '--untracked-files=no']).stdout.strip()