refactor(semantics): migrate legacy @TIER to @COMPLEXITY annotations

- Replaced @TIER: TRIVIAL with @COMPLEXITY: 1
- Replaced @TIER: STANDARD with @COMPLEXITY: 3
- Replaced @TIER: CRITICAL with @COMPLEXITY: 5
- Manually elevated specific critical/complex components to levels 2 and 4
- Ignored legacy, specs, and node_modules directories
- Updated generated semantic map

backend/src/core/auth/logger.py

@@ -1,6 +1,6 @@
 # [DEF:backend.src.core.auth.logger:Module]
 #
-# @TIER:      STANDARD
+# @COMPLEXITY: 3
 # @SEMANTICS: auth, logger, audit, security
 # @PURPOSE:   Audit logging for security-related events.
 # @LAYER:     Core