fix: 部署脚本子进程输出被Python缓冲的问题

子进程Python脚本运行时，Python自动缓冲stdout（因为检测到非TTY）。
设置PYTHONUNBUFFERED=1环境变量，确保所有Python子进程实时输出。

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

deploy.py

@@ -82,17 +82,20 @@ def log_section(msg):
 
 def run_command(cmd, cwd=None, timeout=120, capture=True):
     """执行本地命令"""
+    # 设置 PYTHONUNBUFFERED=1 确保 Python 子进程不缓冲 stdout
+    env = os.environ.copy()
+    env['PYTHONUNBUFFERED'] = '1'
     try:
         if capture:
             result = subprocess.run(
-                cmd, shell=True, cwd=cwd,
+                cmd, shell=True, cwd=cwd, env=env,
                 capture_output=True, text=True, encoding='utf-8', errors='replace',
                 timeout=timeout
             )
             return result.returncode == 0, result.stdout.strip(), result.stderr.strip()
         else:
             result = subprocess.run(
-                cmd, shell=True, cwd=cwd, timeout=timeout
+                cmd, shell=True, cwd=cwd, env=env, timeout=timeout
             )
             return result.returncode == 0, "", ""
     except subprocess.TimeoutExpired: