feat(api,userbot,frontend): search peers without chats and start tracking them

backend/src/api/app.py

@@ -20,6 +20,7 @@ from api.routers import (
     backfill,
     chats,
     custom_emoji,
+    discover,
     events,
     folders,
     media,
@@ -83,6 +84,7 @@ app.include_router(stories.router)
 app.include_router(profile.router)
 app.include_router(events.router)
 app.include_router(peers.router)
+app.include_router(discover.router)
 app.include_router(annotations.router)
 app.include_router(watches.router)