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/api/routes/__init__.py

@@ -1,5 +1,5 @@
 # [DEF:backend.src.api.routes.__init__:Module]
-# @TIER: STANDARD
+# @COMPLEXITY: 3
 # @SEMANTICS: routes, lazy-import, module-registry
 # @PURPOSE: Provide lazy route module loading to avoid heavyweight imports during tests.
 # @LAYER: API
@@ -10,7 +10,7 @@ __all__ = ['plugins', 'tasks', 'settings', 'connections', 'environments', 'mappi
 
 
 # [DEF:__getattr__:Function]
-# @TIER: TRIVIAL
+# @COMPLEXITY: 1
 # @PURPOSE: Lazily import route module by attribute name.
 # @PRE: name is module candidate exposed in __all__.
 # @POST: Returns imported submodule or raises AttributeError.