Defines the public `CrossDomainMatcher` Protocol (PEP 544
@runtime_checkable, two methods: `match` + `health_snapshot`),
the three frozen+slotted DTOs (`CandidateMatchSet`, `MatchResult`,
`MatcherHealth`) in the L1 `_types/matcher.py` layer, the
`MatcherError` family (`MatcherBackboneError`,
`InsufficientInliersError`), and the composition-root
`build_matcher_strategy` factory with lazy-import +
`BUILD_MATCHER_<variant>` gating per ADR-002.
`RollingHealthWindow` accumulator (60 s, amortised O(1) update,
strict O(1) snapshot) is constructed by the factory and injected
into every concrete matcher so all backbones share window
semantics; this is what backs C5's spoof-promotion gate.
Legacy placeholder `MatchResult` removed from `_types/matching.py`;
import-only consumers (`c4_pose.interface`, `c3_5_adhop.interface`)
repointed at the new `_types/matcher.py` home — zero behavioural
change to those components.
AC-9 (single-thread binding) and AC-10 (LightGlueRuntime
identity-share with C2.5) deferred to AZ-270 runtime-root
composition, mirroring the AZ-342 Risk-4 escape clause. All other
ACs + NFRs covered by 70 new conformance tests.
Co-authored-by: Cursor <cursoragent@cursor.com>
Oleksandr Bezdieniezhnykh