rehearsal: ruff production 0 (drop unused agent_def os + server AuthStore imports) and quote 8 unquoted env keys in main-side test tearDowns (latent NameError)

cloud/server.py

@@ -61,7 +61,6 @@ from cloud.agent_def import parse_agent_definition as _parse_agent_definition
 from cloud.agent_def import resolve_registry_agent as _resolve_agent
 from cloud.attempts import ensure_attempts_table as _ensure_attempts
 from cloud.audit_loop import ensure_audit_loop_table as _ensure_audit_loop
-from cloud.auth import AuthStore
 # 演练注：删 _parse_tools_col/_parse_tool_approvals_col（随 helper
 # 移 handler_support）、_MEMBER_ROLES/_coord_parse_parts（用点已随
 # split 移走，server.py 内无其余引用，ruff F401 计）。