fix: add cache-busting to prevent stale JS/CSS from breaking the UI

- Added ?v=20260502 query param to all <script src=...> and <link> tags
- Added Cache-Control: no-cache, no-store, must-revalidate to index route
- Added <meta> cache-control tags in HTML head for extra coverage
- This ensures the browser always fetches fresh HTML/JS/CSS after deploy,
  preventing the old loadLastPrompt() from running against new HTML
  (which would crash since #prompt-cat-info no longer exists)

bot/routes/core.py

@@ -14,7 +14,8 @@ router = APIRouter()
 
 @router.get("/")
 def read_index():
-    return FileResponse("static/index.html")
+    headers = {"Cache-Control": "no-cache, no-store, must-revalidate"}
+    return FileResponse("static/index.html", headers=headers)
 
 
 @router.get("/logs")