feat: Wave 3 - Dashboard redesign + RBAC + AI assistant updates

- Redesign index.html from system-monitor to user-centric workspace
  (welcome banner, summary cards, 今日待办, AI 智能建议, collapsible admin section)
- Add fetchTodos/fetchSuggestions/getPriorityClass/isOverdue methods
- Update uni-nav current-page from 'dashboard' to 'workspace'
- Add require_role to 10 admin router imports (RBAC foundation)
- Update ai-assistant.js: add factory/insights pages, org_id in chat requests

.omo/run-continuation/ses_1dede8a7affeG6DxtfPUOviXrp.json

@@ -1,10 +1,11 @@
 {
   "sessionID": "ses_1dede8a7affeG6DxtfPUOviXrp",
-  "updatedAt": "2026-06-17T07:11:26.600Z",
+  "updatedAt": "2026-06-17T08:18:52.213Z",
   "sources": {
     "background-task": {
-      "state": "idle",
-      "updatedAt": "2026-06-17T07:11:26.600Z"
+      "state": "active",
+      "reason": "2 background task(s) active",
+      "updatedAt": "2026-06-17T08:18:52.213Z"
     }
   }
 }