[AZ-344] C3 CrossDomainMatcher Protocol + factory + RollingHealthWindow

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>

_docs/02_document/contracts/c3_matcher/cross_domain_matcher_protocol.md

@@ -4,8 +4,8 @@
 **Producer task**: AZ-344 (`CrossDomainMatcher` Protocol + factory + composition)
 **Consumer tasks**: AZ-345 (DISK+LightGlue primary), AZ-346 (ALIKED+LightGlue secondary), AZ-347 (XFeat alternate); downstream c3_5_adhop (epic AZ-258) which consumes `MatchResult`
 **Version**: 1.0.0
-**Status**: draft, awaiting AZ-344 implementation
-**Last Updated**: 2026-05-10
+**Status**: v1.0.0 (AZ-344 implemented 2026-05-12)
+**Last Updated**: 2026-05-12
 **Module-layout home**: `src/gps_denied_onboard/components/c3_matcher/interface.py` (Protocol), `src/gps_denied_onboard/components/c3_matcher/__init__.py` (re-exports), `src/gps_denied_onboard/runtime_root/matcher_factory.py` (factory)
 
 ## Purpose
@@ -65,14 +65,13 @@ class CrossDomainMatcher(Protocol):
 
 ```python
 from dataclasses import dataclass
-from uuid import UUID
 import numpy as np
 
 
 @dataclass(frozen=True, slots=True)
 class CandidateMatchSet:
     """Per-candidate matching outcome inside a MatchResult."""
-    tile_id: tuple  # composite (zoomLevel, lat, lon)
+    tile_id: tuple[int, float, float]  # composite (zoomLevel, lat, lon); mirrors VprCandidate / RerankCandidate encoding so the L1 _types layer is free of an L1→L3 import to c6_tile_cache.TileId
     inlier_count: int
     inlier_correspondences: np.ndarray  # shape (I, 4) float32; (px_query, py_query, px_tile, py_tile)
     ransac_outlier_count: int
@@ -82,8 +81,8 @@ class CandidateMatchSet:
 @dataclass(frozen=True, slots=True)
 class MatchResult:
     """Cross-domain match outcome for one frame. Consumed by C3.5 ConditionalRefiner."""
-    frame_id: UUID
-    per_candidate: list[CandidateMatchSet]  # 0 < len <= N=3, ranked by inlier_count descending; ties broken by per_candidate_residual_px ascending
+    frame_id: int  # mirrors NavCameraFrame.frame_id; matches AZ-336 / AZ-342 encoding
+    per_candidate: tuple[CandidateMatchSet, ...]  # 0 < len <= N=3, ranked by inlier_count descending; ties broken by per_candidate_residual_px ascending. tuple (not list) so frozen+slots actually holds.
     best_candidate_idx: int  # 0 by construction (sorted)
     reprojection_residual_px: float  # best candidate's median residual
     matched_at: int  # monotonic_ns
@@ -115,6 +114,8 @@ class InsufficientInliersError(MatcherError):
     """Every candidate failed OR every candidate's inlier count is below `config.matcher.min_inliers_threshold`. Raised by `match`. C5 falls back to VIO-only."""
 ```
 
+The composition-time selection error is **`StrategyNotAvailableError`** (`runtime_root.errors`), NOT a member of `MatcherError`: it surfaces when the binary lacks the requested `BUILD_MATCHER_<variant>` flag or the concrete strategy module is not built yet (AZ-345..AZ-347 pending). This matches the C2 VPR (AZ-336) and C2.5 ReRank (AZ-342) factory pattern: per-frame matcher errors live in the C3 family; composition-time selection errors live in the shared runtime-root family.
+
 ## Composition-Root Factory
 
 ```python

_docs/02_document/module-layout.md

@@ -70,15 +70,18 @@ Bootstrap reference: `_docs/02_tasks/todo/AZ-263_initial_structure.md`. Architec
 - **Epic**: AZ-257 (E-C3 Cross-Domain Matcher)
 - **Directory**: `src/gps_denied_onboard/components/c3_matcher/`
 - **Public API**:
-  - `__init__.py` (re-exports `CrossDomainMatcher`, `MatchResult`)
+  - `__init__.py` (re-exports `CrossDomainMatcher`, `MatchResult`, `MatcherHealth`, `CandidateMatchSet`, `MatcherError`, `MatcherBackboneError`, `InsufficientInliersError`, `C3MatcherConfig`)
   - `interface.py` (`CrossDomainMatcher` Protocol)
+  - `config.py` (`C3MatcherConfig`)
+  - `errors.py` (error hierarchy)
 - **Internal**:
-  - `disk_lightglue.py` (DISK + LightGlue)
-  - `aliked_lightglue.py` (ALIKED + LightGlue)
-  - `xfeat.py`
+  - `_health_window.py` (`RollingHealthWindow` accumulator; constructor-injected into every concrete matcher)
+  - `disk_lightglue.py` (DISK + LightGlue, AZ-345)
+  - `aliked_lightglue.py` (ALIKED + LightGlue, AZ-346)
+  - `xfeat.py` (XFeat, AZ-347)
   - `_native/`
-- **Owns**: `src/gps_denied_onboard/components/c3_matcher/**`, `tests/unit/c3_matcher/**`
-- **Imports from**: `_types`, `helpers.lightglue_runtime` (R14: SHARED with C2.5 — owned by helper, NOT by C3), `helpers.descriptor_normaliser`, `helpers.se3_utils`, `components.c7_inference`, `config`, `logging`, `fdr_client`
+- **Owns**: `src/gps_denied_onboard/components/c3_matcher/**`, `tests/unit/c3_matcher/**`, `src/gps_denied_onboard/runtime_root/matcher_factory.py`
+- **Imports from**: `_types`, `helpers.lightglue_runtime` (R14: SHARED with C2.5 — owned by helper, NOT by C3), `helpers.ransac_filter`, `helpers.descriptor_normaliser`, `helpers.se3_utils`, `components.c7_inference`, `config`, `logging`, `fdr_client`
 - **Consumed by**: `c3_5_adhop`, `runtime_root`
 
 ### Component: c3_5_adhop