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

frontend/src/components/__tests__/task_log_viewer.test.js

@@ -1,5 +1,5 @@
 // [DEF:frontend.src.components.__tests__.task_log_viewer:Module]
-// @TIER: STANDARD
+// @COMPLEXITY: 3
 // @SEMANTICS: tests, task-log, viewer, mount, components
 // @PURPOSE: Unit tests for TaskLogViewer component by mounting it and observing the DOM.
 // @LAYER: UI (Tests)