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/lib/components/assistant/AssistantChatPanel.svelte

@@ -1,7 +1,7 @@
 <!-- [DEF:AssistantChatPanel:Component] -->
 <script>
   /**
-   * @TIER: CRITICAL
+   * @COMPLEXITY: 5
    * @PURPOSE: Slide-out assistant chat panel for natural language command execution and task tracking.
    * @LAYER: UI
    * @RELATION: BINDS_TO -> assistantChatStore