feat(client-verification): add client verification (#104)

New configurations:

- `CHECK_CLIENT_VERSION` enables the check (default=True)
- `CLIENT_VERSION_URLS` contains a chain of valid client hashes. [osu!](https://osu.ppy.sh/home/download) and [osu! GU](https://github.com/GooGuTeam/osu/releases) are valid by default. View [g0v0-client-versions](https://github.com/GooGuTeam/g0v0-client-versions) to learn how to support your own client.

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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

main.py

@@ -33,6 +33,7 @@ from app.router.redirect import redirect_router
 from app.router.v1 import api_v1_public_router
 from app.service.beatmap_download_service import download_service
 from app.service.beatmapset_update_service import init_beatmapset_update_service
+from app.service.client_verification_service import init_client_verification_service
 from app.service.email_queue import start_email_processor, stop_email_processor
 from app.service.redis_message_system import redis_message_system
 from app.service.subscribers.user_cache import user_online_subscriber
@@ -68,6 +69,9 @@ async def lifespan(app: FastAPI):  # noqa: ARG001
     load_achievements()
     await init_calculator()
 
+    if settings.check_client_version:
+        await init_client_verification_service()
+
     # init rate limiter
     await FastAPILimiter.init(redis_rate_limit_client)