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, 6 insertions, 7 deletions

diff --git a/packages/meshbay-hub/tests/test_session_lifetime.py b/packages/meshbay-hub/tests/test_session_lifetime.py
index af73767..3a1f47a 100644
--- a/packages/meshbay-hub/tests/test_session_lifetime.py
+++ b/packages/meshbay-hub/tests/test_session_lifetime.py
@@ -6,13 +6,12 @@ maximum — plus a sign-out the hub honours and "sign out everywhere". The
 browser half is `test_browser_idle_signout.py`; this is the hub's.
 """
 
-from datetime import datetime, timedelta, timezone
+from datetime import UTC, datetime, timedelta
 
 import pytest
-from sqlalchemy import select, update
-
 from meshbay_hub.api.deps import set_admin_usernames
 from meshbay_hub.db.models import RefreshToken, User
+from sqlalchemy import select, update
 
 AUTH_KEY = "s" * 44
 
@@ -40,7 +39,7 @@ async def _refresh(client, token):
 
 
 def _aware(dt):
-    return dt if dt.tzinfo else dt.replace(tzinfo=timezone.utc)
+    return dt if dt.tzinfo else dt.replace(tzinfo=UTC)
 
 
 async def _expiry(db_session, username):
@@ -66,7 +65,7 @@ async def test_the_defaults_are_in_the_panel_and_the_browser_delay_is_public(cli
 async def test_a_refresh_token_lasts_the_idle_window(client, db_session):
     await _register(client, "idle_window")
     await _login(client, "idle_window")
-    left = await _expiry(db_session, "idle_window") - datetime.now(timezone.utc)
+    left = await _expiry(db_session, "idle_window") - datetime.now(UTC)
     assert timedelta(hours=23, minutes=58) < left <= timedelta(hours=24)
 
 
@@ -78,7 +77,7 @@ async def test_the_idle_window_never_undercuts_the_access_token(client, db_sessi
                        json={"session": {"refresh_idle_hours": 1}})
     await _register(client, "short_idle")
     await _login(client, "short_idle")
-    left = await _expiry(db_session, "short_idle") - datetime.now(timezone.utc)
+    left = await _expiry(db_session, "short_idle") - datetime.now(UTC)
     # The test hub's access token lives 3600 s; the floor is that plus an hour.
     assert left > timedelta(hours=1, minutes=58)
 
@@ -98,7 +97,7 @@ async def test_no_session_renews_past_its_maximum(client, db_session):
         select(User.id).where(User.username == "long_session"))).scalar_one()
     await db_session.execute(
         update(RefreshToken).where(RefreshToken.user_id == uid)
-        .values(created_at=datetime.now(timezone.utc) - timedelta(hours=721)))
+        .values(created_at=datetime.now(UTC) - timedelta(hours=721)))
     await db_session.commit()
 
     r = await _refresh(client, current)