State the cv.boolean alignment at the definition

esphome/helpers.py

@@ -395,6 +395,12 @@ def sort_ip_addresses(address_list: list[str]) -> list[str]:
 
 
 def get_bool_env(var, default=False):
+    """Read a boolean environment knob.
+
+    Accepts the same spellings as ``cv.boolean`` does in YAML, so the
+    environment speaks the config language's boolean dialect; anything
+    unrecognized falls through to ``bool(value)``.
+    """
     value = os.getenv(var, default)
     if isinstance(value, str):
         value = value.lower()

tests/unit_tests/test_helpers.py

@@ -1124,6 +1124,6 @@ def test_format_duration(seconds: float, expected: str) -> None:
 def test_get_bool_env_common_spellings(
     monkeypatch: pytest.MonkeyPatch, value: str, expected: bool
 ) -> None:
-    """The common on/off spellings parse instead of reading as truthy."""
+    """The cv.boolean spellings parse instead of reading as truthy."""
     monkeypatch.setenv("SOME_KNOB", value)
     assert helpers.get_bool_env("SOME_KNOB") is expected