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, 2 insertions, 1 deletions

diff --git a/packages/meshbay-node/tests/test_index_no_cleartext.py b/packages/meshbay-node/tests/test_index_no_cleartext.py
index e5e4555..30d1226 100644
--- a/packages/meshbay-node/tests/test_index_no_cleartext.py
+++ b/packages/meshbay-node/tests/test_index_no_cleartext.py
@@ -14,7 +14,6 @@ framing or in a field name.
 
 import msgpack
 import pytest
-from conftest import one_root
 from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey
 from meshbay_common.crypto import generate_gek
 from meshbay_common.groupbox import PURPOSE_ACK, PURPOSE_INDEX, seal, unseal
@@ -22,6 +21,8 @@ from meshbay_common.protocol import MNP
 from meshbay_node.indexer import DirectoryIndexer, GroupIndex
 from meshbay_node.transport.wire import index_delta_message, index_sync_message
 
+from conftest import one_root
+
 # A filename and a folder name that appear nowhere else in the tree.
 SECRET_FILE = "quixotry-ledger-2019.pdf"
 SECRET_DIR = "zarfwidget-archive"