test(safety): add Phase E comprehensive safety tests

- Add tests for models: ActionMetadata, ActionRequest, ActionResult,
  ValidationRule, BudgetStatus, RateLimitConfig, ApprovalRequest/Response,
  Checkpoint, RollbackResult, AuditEvent, SafetyPolicy, GuardianResult
- Add tests for validation: ActionValidator rules, priorities, patterns,
  bypass mode, batch validation, rule creation helpers
- Add tests for loops: LoopDetector exact/semantic/oscillation detection,
  LoopBreaker throttle/backoff, history management
- Add tests for content filter: PII filtering (email, phone, SSN, credit card),
  secret blocking (API keys, GitHub tokens, private keys), custom patterns,
  scan without filtering, dict filtering
- Add tests for emergency controls: state management, pause/resume/reset,
  scoped emergency stops, callbacks, EmergencyTrigger events
- Fix exception kwargs in content filter and emergency controls to match
  exception class signatures

All 108 tests passing with lint and type checks clean.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/app/services/safety/emergency/controls.py

@@ -328,7 +328,7 @@ class EmergencyControls:
                 if raise_if_blocked:
                     raise EmergencyStopError(
                         f"Global emergency state: {self._global_state.value}",
-                        stop_reason=self._get_last_reason("global"),
+                        stop_type=self._get_last_reason("global") or "emergency",
                         triggered_by=self._get_last_triggered_by("global"),
                     )
                 return False
@@ -340,9 +340,9 @@ class EmergencyControls:
                     if raise_if_blocked:
                         raise EmergencyStopError(
                             f"Emergency state for {scope}: {state.value}",
-                            stop_reason=self._get_last_reason(scope),
+                            stop_type=self._get_last_reason(scope) or "emergency",
                             triggered_by=self._get_last_triggered_by(scope),
-                            scope=scope,
+                            details={"scope": scope},
                         )
                     return False