feat: add Citations and WatchlistChat components, integrate with API

- Implemented Citations component to display citation data.
- Created WatchlistDrawer and ChatSidebar components for managing watchlists and AI chat functionality.
- Integrated API calls for watchlist management and chat interactions.
- Updated index.tsx to include new components in the main application layout.
- Added API client in lib/api.ts for structured API interactions.
- Developed Alerts, Dashboard, Portfolio, Routines, Screener, and Report pages with relevant data fetching and UI components.
- Introduced styles in tokens.css for consistent theming across the application.
- Configured TypeScript and Vite for project setup and development.

backend/tests/fixtures/brokers_top_idx.json

@@ -0,0 +1,32 @@
+{
+ "date": "2026-09-11",
+ "metric": "net",
+ "origin": "all",
+ "cohort": "all",
+ "results": [
+  {
+   "rank": 1,
+   "broker_code": "MG",
+   "gross": 1080000000000,
+   "net": 520000000000
+  },
+  {
+   "rank": 2,
+   "broker_code": "AK",
+   "gross": 990000000000,
+   "net": 410000000000
+  },
+  {
+   "rank": 3,
+   "broker_code": "CC",
+   "gross": 710000000000,
+   "net": 290000000000
+  },
+  {
+   "rank": 4,
+   "broker_code": "BK",
+   "gross": 580000000000,
+   "net": -180000000000
+  }
+ ]
+}