[AZ-343] C2.5 InlierCountReRanker + shared FeatureExtractor helper

Implements the production-default ReRankStrategy: K=10 → N=3 by
single-pair LightGlue inlier count, with strict drop-and-continue
(INV-8) on per-candidate TileFetch / backbone / zero-inlier failures
and RerankAllCandidatesFailedError on zero survivors. Composition
root injects the shared LightGlueRuntime + Clock + the new
FeatureExtractor helper (an L1 placeholder OpenCvOrbExtractor that
unblocks AZ-343 and future C3 strategies — task scope expansion).

Architectural notes:
- Cross-component imports stay banned; tile_store types as `object`
  and the C6 TileCacheError family is duck-typed by class module
  prefix (same workaround AZ-348 adopted for c7_inference; proper
  fix is to relocate TileCacheError to _types/ in a follow-up).
- Clock injection follows the replay contract (AZ-398 Invariant 2);
  reranked_at is sourced from clock.monotonic_ns().
- AZ-342 factory grew `feature_extractor` + `clock` + `fdr_client`
  parameters; existing AZ-342 conformance tests updated.

Tests: 19 new AC-1..AC-12 + mixed-failure scenarios in
test_inlier_count_reranker.py; existing AZ-342 suite (26) still
green. Full repo sweep 1093 passed / 2 skipped (cmake/actionlint
not on PATH).

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/unit/c2_5_rerank/test_protocol_conformance.py

@@ -70,11 +70,46 @@ class _FakeLightGlueRuntime:
         raise NotImplementedError
 
 
+class _FakeFeatureExtractor:
+    def descriptor_dim(self):
+        return 256
+
+    def extract(self, image_bgr):
+        raise NotImplementedError
+
+
+class _FakeClock:
+    def __init__(self) -> None:
+        self._t = 1_000_000_000
+
+    def monotonic_ns(self):
+        self._t += 1
+        return self._t
+
+    def time_ns(self):
+        return self._t
+
+    def sleep_until_ns(self, target_ns):
+        return None
+
+
 class _FullReRankStrategy:
-    def __init__(self, config, *, tile_store, lightglue_runtime) -> None:
+    def __init__(
+        self,
+        config,
+        *,
+        tile_store,
+        lightglue_runtime,
+        feature_extractor=None,
+        clock=None,
+        fdr_client=None,
+    ) -> None:
         self._config = config
         self._tile_store = tile_store
         self._lightglue_runtime = lightglue_runtime
+        self._feature_extractor = feature_extractor
+        self._clock = clock
+        self._fdr_client = fdr_client
         self._label = config.components["c2_5_rerank"].strategy
 
     def rerank(self, frame, vpr_result, n, calibration):
@@ -127,6 +162,7 @@ def test_ac1_rerank_strategy_conformance_full() -> None:
         _config_with_strategy(),
         tile_store=_FakeTileStore(),
         lightglue_runtime=_FakeLightGlueRuntime(),
+        clock=_FakeClock(),
     )
     assert isinstance(instance, ReRankStrategy)
 
@@ -201,6 +237,8 @@ def test_ac3_factory_rejects_missing_build_flag(
                 config,
                 tile_store=_FakeTileStore(),
                 lightglue_runtime=_FakeLightGlueRuntime(),
+                feature_extractor=_FakeFeatureExtractor(),
+                clock=_FakeClock(),
             )
     assert "BUILD_RERANK_INLIER_COUNT is OFF" in str(exc_info.value)
     assert any(
@@ -219,6 +257,8 @@ def test_ac3_factory_does_not_load_module_when_flag_off(
             config,
             tile_store=_FakeTileStore(),
             lightglue_runtime=_FakeLightGlueRuntime(),
+            feature_extractor=_FakeFeatureExtractor(),
+            clock=_FakeClock(),
         )
     assert module_name not in sys.modules
 
@@ -256,6 +296,8 @@ def test_ac5_factory_emits_info_log_on_success(
             config,
             tile_store=_FakeTileStore(),
             lightglue_runtime=_FakeLightGlueRuntime(),
+            feature_extractor=_FakeFeatureExtractor(),
+            clock=_FakeClock(),
         )
     assert isinstance(instance, ReRankStrategy)
     records = [
@@ -281,6 +323,8 @@ def test_ac6_strategy_resolution(monkeypatch, strategy_module_cleanup) -> None:
         config,
         tile_store=_FakeTileStore(),
         lightglue_runtime=_FakeLightGlueRuntime(),
+        feature_extractor=_FakeFeatureExtractor(),
+        clock=_FakeClock(),
     )
     assert isinstance(instance, fake_cls)
     assert isinstance(instance, ReRankStrategy)
@@ -373,12 +417,18 @@ def test_nfr_perf_factory_under_50ms_p99(
     config = _config_with_strategy(strategy)
     tile_store = _FakeTileStore()
     lightglue_runtime = _FakeLightGlueRuntime()
+    feature_extractor = _FakeFeatureExtractor()
+    clock = _FakeClock()
 
     durations_ms: list[float] = []
     for _ in range(100):
         t0 = time.perf_counter()
         build_rerank_strategy(
-            config, tile_store=tile_store, lightglue_runtime=lightglue_runtime
+            config,
+            tile_store=tile_store,
+            lightglue_runtime=lightglue_runtime,
+            feature_extractor=feature_extractor,
+            clock=clock,
         )
         durations_ms.append((time.perf_counter() - t0) * 1000.0)