ruff --select UP007,UP045 --fix converted ~1760 sites across the
backend: `Optional[T]` → `T | None`, `Union[X, Y]` → `X | Y`. The
remaining module-level alias targets that ruff conservatively skips
(BindableFloatInput, ColorList, DeviceConfig) were converted by hand
earlier in the pass. black -formatted the result so the wider unions
fit cleanly under the 100-char line budget.
pyproject.toml now sets [tool.ruff.lint] extend-select = ["UP007",
"UP045"] so future legacy imports fire CI on every push. The
pre-commit ruff hook was bumped from v0.8.0 -> v0.15.12 to recognise
UP045 (split off from UP007 in v0.13).
``_target_to_response`` in ``api/routes/output_targets.py`` used to be
an isinstance ladder over the three OutputTarget subclasses with a
silent fallback that fabricated a ``LedOutputTargetResponse`` for
unknown types (audit finding H3). The fallback masked exactly the
kind of bug we hit on the CSS side in Phase 1.1: a new target subclass
slipped past the ladder and got mis-shaped on the wire.
Replace the ladder with a ``_TARGET_RESPONSE_BUILDERS`` dict keyed by
the concrete subclass plus an import-time
``_assert_target_response_coverage()`` that requires the registry to
exactly match ``{WledOutputTarget, HALightOutputTarget,
Z2MLightOutputTarget}``. ``_target_to_response`` now raises
``RuntimeError`` instead of silently fabricating a LED response for an
unknown subclass — coverage is asserted at import so this branch is
unreachable in normal operation.
Tests: 5 new regression tests cover bijection between expected classes
and registered builders, callable shape, the rogue-target-raises
contract, and missing/extra entry rejection in the assertion. 24
existing output-target tests stay green; ruff clean.
alexei.dolgolyov