perf(api,frontend): index hot queries, paginate chats, fix realtime

backend/src/api/routers/media.py

@@ -5,6 +5,7 @@ from dishka.integrations.fastapi import DishkaRoute, FromDishka
 from fastapi import APIRouter, HTTPException, Query
 from fastapi.responses import FileResponse
 
+from utils.cache import DAY_HEADERS, IMMUTABLE_HEADERS
 from utils.read.media import (
     get_media,
     get_media_version,
@@ -47,6 +48,7 @@ async def serve_media_version(
     return FileResponse(
         storage.url(version.storage_key),
         media_type=version.mime or "application/octet-stream",
+        headers=IMMUTABLE_HEADERS,
     )
 
 
@@ -80,4 +82,5 @@ async def serve_media(
     return FileResponse(
         storage.url(media.storage_key),
         media_type=media.mime or "application/octet-stream",
+        headers=DAY_HEADERS,
     )