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/content/filter.py

@@ -370,8 +370,8 @@ class ContentFilter:
             if raise_on_block:
                 raise ContentFilterError(
                     block_reason or "Content blocked",
-                    detected_category=all_matches[0].category.value if all_matches else "unknown",
-                    pattern_name=all_matches[0].pattern_name if all_matches else None,
+                    filter_type=all_matches[0].category.value if all_matches else "unknown",
+                    detected_patterns=[m.pattern_name for m in all_matches] if all_matches else [],
                 )
         elif all_matches:
             logger.debug(