feat: block direct MCP imports and unsanctioned keychain access (Closes #558)

Require a sanctioned MCP daemon (or pytest) before get_auth_header and
keychain credential fill so raw shell imports cannot bypass preflight gates.

docs/llm-workflow-runbooks.md

@@ -408,6 +408,14 @@ The guard blocks when the **control checkout** (repository root) is:
 `branches/...` directories are disposable role worktrees; the root checkout is
 the stable orchestration surface only.
 
+
+## No direct-import mutation path (#558)
+
+Never `import gitea_mcp_server` or call `gitea_auth.get_auth_header` /
+keychain fill from a raw shell to bypass MCP preflight.
+
+Use the official MCP daemon only. See [`docs/mcp-daemon-import-guard.md`](mcp-daemon-import-guard.md).
+
 ## Shell Spawn Hard-Stop Rule
 
 Symptom: a shell tool call returns `exit_code: -1` with empty stdout/stderr.