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/top_changes_idx.json

@@ -0,0 +1,16 @@
+{
+ "top_gainers": {
+  "1d": [
+   {
+    "name": "Bank Central Asia",
+    "symbol": "BBCA.JK",
+    "price_change": 0.032,
+    "last_close_price": 9950,
+    "latest_close_date": "2026-09-11"
+   }
+  ]
+ },
+ "top_losers": {
+  "1d": []
+ }
+}