fix(guard): close allow_test_bootstrap and basename entrypoint bypasses (#695)

Remove the public allow_test_bootstrap production seam so caller-controlled
flags cannot forge native mutation provenance. Bind provenance to the resolved
canonical entrypoint path plus a live stdio transport bind; basename-only
mcp_server.py stack frames and import-only launch no longer authorize
mutations. Test-mode install_test_native_runtime is pytest-only and cannot
reach production Gitea mutation endpoints. Add AC9 regressions for both
reviewer-found bypasses and related spoof vectors.

Refs: PR #696 REQUEST_CHANGES at 253269c; issue #695 comments 11002/11005.

mcp_server.py

@@ -41,15 +41,17 @@ def check_conflict_markers():
 
 check_conflict_markers()
 
-# #558: official entrypoint marks the process as the sanctioned MCP daemon
-# before loading mutation modules (blocks raw shell import bypasses).
+# #558 / #695: claim the official entrypoint before loading mutation modules.
+# This alone does NOT authorize mutations — gitea_mcp_server binds the live
+# native MCP transport (stdio) immediately before mcp.run. Import-only or
+# offline launch without that bind fails closed on mutations.
 try:
     import mcp_daemon_guard
 
     mcp_daemon_guard.mark_sanctioned_daemon()
 except Exception:
     # Guard import failures must not hide conflict-marker infra_stop above;
-    # gitea_mcp_server main also marks sanctioned when run as __main__.
+    # gitea_mcp_server main also marks + binds when run as __main__.
     pass
 
 # Execute the actual server logic via exec in this namespace.