feat(backend): add v2 LLM validation fields to health service

- DashboardHealthItem schema: add run_id, policy_id, execution_path,
  issues_count, timings, token_usage, screenshot_paths, chunk_count,
  dashboard_name fields for v2 LLM validation reporting.
- HealthService: populate v2 fields from validation run records.
- ValidationService: update to support v2 validation run fields.
- validation_tasks route: minor fix for v2 field handling.
- tailwind.config.js: refactor design tokens — add success/warning/info
  palettes, surface/border/text hierarchy, semantic action colors.
- Agent configs: update svelte-coder and semantics-svelte for
  .svelte.ts runes and Screen Model patterns.

backend/src/api/routes/validation_tasks.py

@@ -308,6 +308,7 @@ async def list_all_runs(
     page_size: int = Query(20, ge=1, le=100),
     status_filter: str | None = Query(None, alias="status", description="Filter by status"),
     environment_id: str | None = Query(None, description="Filter by environment"),
+    dashboard_id: str | None = Query(None, description="Filter by dashboard ID"),
     current_user: User = Depends(get_current_user),
     _=Depends(has_permission("validation.run", "VIEW")),
     service: ValidationTaskService = Depends(_get_task_service),
@@ -319,7 +320,8 @@ async def list_all_runs(
     )
     try:
         total, raw_items = service.list_all_runs(
-            status=status_filter, environment_id=environment_id, page=page, page_size=page_size,
+            status=status_filter, environment_id=environment_id, dashboard_id=dashboard_id,
+            page=page, page_size=page_size,
         )
         return RecordListResponse(items=raw_items, total=total, page=page, page_size=page_size)
     except ValueError as e: