style: say which lint rules this repo keeps, then keep them

`[tool.ruff]` set a line length and a target version and nothing else, so which
rules ran depended on the installed ruff's defaults — fine while nobody ran it,
not fine for a CI job that can turn a push red because a tool changed its mind.

The set is named explicitly (E, F, I, UP, SIM, B, RUF) with three ignores that
are each a real decision rather than a shrug: B008, because FastAPI's whole
dependency idiom is a call in a default argument; E501, because wrapping prose
is a formatter's business; and RUF001, because the reports and the bot speak
Russian and "ambiguous character" is the wrong complaint about a string the
user is meant to read.

The 73 findings that remained are fixed — mostly `datetime.timezone.utc` →
`datetime.UTC`, `typing.Callable` → `collections.abc.Callable`, import order,
and unused `noqa` markers — plus seven by hand: `contextlib.suppress` for two
try/except/pass pairs, unpacking instead of list concatenation, one negated
return.

`ruff format` is deliberately *not* adopted: it would reformat 51 files, and
some of the layout here is hand-set (the comment tables, the DNS wire-format
structs) in ways a formatter flattens.

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

desktop/kadence_desktop/blocking/manager.py

@@ -26,8 +26,8 @@ from __future__ import annotations
 
 import logging
 import time
+from collections.abc import Callable
 from types import ModuleType
-from typing import Callable
 
 from kadence_desktop.blocking import processes
 from kadence_desktop.blocking.hosts import HostsBlocker
@@ -262,7 +262,7 @@ class BlockerManager:
                 self._asked[identity] = now
                 self._announce(app, "killed")
 
-    def _announce(self, app: "processes.RunningApp", action: str) -> None:
+    def _announce(self, app: processes.RunningApp, action: str) -> None:
         """Report and notify, at most once per process per cooldown."""
         if not self._claim_report(app.identity):
             return