style: ruff's own fixes, mechanically applied

`ruff check .` had gone unrun long enough to report 568 errors, which is the
same as having no linter: the next real finding would have been invisible in the
noise. This is the 521 it fixes by itself, in 173 files, and nothing else — the
98 it cannot fix are the next commit.

What actually changed: import sorting (225), imports nobody used (87, none of
them a re-export — no `__init__.py` is touched, which was the one way this could
have broken an import elsewhere), `datetime.timezone.utc` to `datetime.UTC` (69)
and `asyncio.TimeoutError` to `TimeoutError` (18), both plain aliases on the 3.12
this project requires, `Optional[X]` to `X | None` (24), and f-strings with
nothing to interpolate (19).

Checked rather than assumed: every module in the three packages still imports,
and the suite is 2893 passed — the same count, test for test, as the merge
before it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

1 files changed, 23 insertions, 19 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/app.py b/packages/meshbay-hub/src/meshbay_hub/app.py
index afc1cde..209dc32 100644
--- a/packages/meshbay-hub/src/meshbay_hub/app.py
+++ b/packages/meshbay-hub/src/meshbay_hub/app.py
@@ -11,37 +11,41 @@ Usage:
 
 import asyncio
 from contextlib import asynccontextmanager
-from pathlib import Path
 
 from fastapi import FastAPI
 from slowapi import _rate_limit_exceeded_handler
 from slowapi.errors import RateLimitExceeded
 
 from meshbay_hub import __version__
+from meshbay_hub.api.admin import router as admin_router
+from meshbay_hub.api.deps import set_admin_usernames
+from meshbay_hub.api.federation import router as federation_router
+from meshbay_hub.api.groups import router as groups_router
+from meshbay_hub.api.groups import swarm_router
+from meshbay_hub.api.health import router as health_router
+from meshbay_hub.api.hub import router as hub_router
+from meshbay_hub.api.hub import set_config as hub_set_config
+from meshbay_hub.api.middleware import limiter
+from meshbay_hub.api.moderation import router as moderation_router
+from meshbay_hub.api.nodes import router as nodes_router
+from meshbay_hub.api.notifications import router as notifications_router
+from meshbay_hub.api.relay import router as relay_router
+from meshbay_hub.api.revocation import router as revocation_router
+from meshbay_hub.api.signaling import router as signaling_router
+from meshbay_hub.api.users import router as users_router
+from meshbay_hub.api.users import set_config as users_set_config
+from meshbay_hub.api.webapp import ASSET_V, CSP, STATIC_DIR
+from meshbay_hub.api.webapp import router as webapp_router
 from meshbay_hub.auth import generate_hub_keypair, load_hub_keypair
 from meshbay_hub.config import HubConfig
+from meshbay_hub.csam import csam_router
 from meshbay_hub.db.engine import close_db, init_db
-from meshbay_hub.api.hub        import router as hub_router, set_config as hub_set_config
-from meshbay_hub.api.users      import router as users_router, set_config as users_set_config
-from meshbay_hub.api.deps       import set_admin_usernames
-from meshbay_hub.api.nodes      import router as nodes_router
-from meshbay_hub.api.groups     import router as groups_router, swarm_router
-from meshbay_hub.api.revocation  import router as revocation_router
-from meshbay_hub.api.moderation  import router as moderation_router
-from meshbay_hub.api.federation  import router as federation_router
-from meshbay_hub.csam            import csam_router
-from meshbay_hub.api.health      import router as health_router
-from meshbay_hub.api.relay       import router as relay_router
-from meshbay_hub.api.signaling   import router as signaling_router
-from meshbay_hub.api.admin       import router as admin_router
-from meshbay_hub.api.notifications import router as notifications_router
-from meshbay_hub.api.webapp     import router as webapp_router, STATIC_DIR, ASSET_V, CSP
-from meshbay_hub.api.middleware import limiter
 
 
 async def _sync_admin_roles(admin_usernames: list[str]) -> None:
     """Ensure config-listed admin usernames have role='admin' in the DB."""
-    from sqlalchemy import select, update
+    from sqlalchemy import select
+
     from meshbay_hub.db.engine import get_session_factory
     from meshbay_hub.db.models import User
 
@@ -122,8 +126,8 @@ def create_app(cfg: HubConfig | None = None) -> FastAPI:
         from meshbay_hub.csam import get_csam_checker
         get_csam_checker().load()
 
-        from meshbay_hub.tasks.cleanup import cleanup_loop
         from meshbay_hub.db.engine import get_session_factory
+        from meshbay_hub.tasks.cleanup import cleanup_loop
         cleanup_task = asyncio.create_task(cleanup_loop(get_session_factory()))
 
         yield