fix: type-check against python 3.14, as the runner does (#42)

The new typing step failed on its first CI run — not on our code:
mypy parses the sources of the installed homeassistant, and after #392
that is HA 2026.8.3 on python 3.14, which uses 3.14-only syntax
(parenthesis-free `except`). With python_version = 3.13 mypy stopped at
a syntax error in someone else's file before reaching a single module of
ours, which is exactly the silent-nothing the gate exists to prevent —
except loud.

ruff keeps target-version py313 deliberately: it lints OUR sources and a
lower target only withholds newer-syntax suggestions, while mypy has to
read the dependency tree the runner actually installs.

User-Visible: no
Issue: #42

pyproject.toml

@@ -11,7 +11,11 @@ select = ["E", "F", "B", "I"]
 ignore = ["E501"]
 
 [tool.mypy]
-python_version = "3.13"
+# 3.14, как и раннер после #392: mypy разбирает исходники установленного
+# homeassistant, а тот уже написан на синтаксисе 3.14 (`except` без скобок) —
+# на более низком python_version проверка падает синтаксической ошибкой в
+# чужом файле, не дойдя до наших модулей.
+python_version = "3.14"
 explicit_package_bases = true
 mypy_path = "."
 # Strict is opt-in per module (#42): the allowlist below only ever GROWS —