fix: qrcode 补入 dependencies（0.1.0 遗留，templates qrcode 模板硬依赖）；requirements 冻结 mcp==1.29.0

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

requirements.txt

@@ -1,6 +1,8 @@
 androguard==4.1.4
 bleak==3.0.2
 capstone==5.0.9
+# MCP 服务器依赖；钉版理由见 DECISIONS 2026-07-31；本文件为 GOVERNANCE 指定的依赖冻结
+mcp==1.29.0
 pillow==12.3.0
 pytest==9.1.1
 pytest-asyncio==1.4.0