[AZ-230] Add local VPR retrieval boundary

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

tests/unit/test_satellite_service_vpr.py

@@ -0,0 +1,104 @@
+from satellite_service import (
+    LocalVprIndexPackage,
+    LocalVprRetriever,
+    RelocalizationRequest,
+    VprDescriptorRecord,
+)
+
+
+def _record(
+    chunk_id: str = "chunk-1",
+    tile_id: str = "tile-1",
+    descriptor: tuple[float, ...] = (1.0, 0.0, 0.0),
+    freshness_status: str = "fresh",
+) -> VprDescriptorRecord:
+    return VprDescriptorRecord(
+        chunk_id=chunk_id,
+        tile_id=tile_id,
+        descriptor=descriptor,
+        footprint={"min_lat": 49.0, "max_lat": 49.1, "min_lon": 36.0, "max_lon": 36.1},
+        freshness_status=freshness_status,
+    )
+
+
+def test_valid_local_index_load_reports_ready_status() -> None:
+    # Arrange
+    retriever = LocalVprRetriever()
+    package = LocalVprIndexPackage(package_id="index-1", records=(_record(),))
+
+    # Act
+    readiness = retriever.load_index(package)
+
+    # Assert
+    assert readiness.ready is True
+    assert readiness.engine == "cpu_faiss"
+    assert readiness.loaded_records == 1
+
+
+def test_loaded_index_returns_bounded_candidates_with_freshness() -> None:
+    # Arrange
+    retriever = LocalVprRetriever()
+    retriever.load_index(
+        LocalVprIndexPackage(
+            package_id="index-1",
+            records=(
+                _record(chunk_id="chunk-best", tile_id="tile-best", descriptor=(1.0, 0.0)),
+                _record(
+                    chunk_id="chunk-stale",
+                    tile_id="tile-stale",
+                    descriptor=(0.8, 0.2),
+                    freshness_status="stale",
+                ),
+            ),
+        )
+    )
+    request = RelocalizationRequest(
+        frame_id="frame-1",
+        image_ref="replay/frame-1.jpg",
+        trigger_reason="covariance_growth",
+        top_k=1,
+        query_descriptor=(1.0, 0.0),
+    )
+
+    # Act
+    result = retriever.retrieve(request)
+
+    # Assert
+    assert result.degraded is False
+    assert len(result.candidates) == 1
+    assert result.candidates[0].chunk_id == "chunk-best"
+    assert result.candidates[0].tile_id == "tile-best"
+    assert result.candidates[0].freshness_status == "fresh"
+
+
+def test_missing_index_degrades_with_explicit_no_candidate_result() -> None:
+    # Arrange
+    retriever = LocalVprRetriever()
+    request = RelocalizationRequest(
+        frame_id="frame-1",
+        image_ref="replay/frame-1.jpg",
+        trigger_reason="cold_start",
+        top_k=3,
+    )
+
+    # Act
+    result = retriever.retrieve(request)
+
+    # Assert
+    assert result.ready is False
+    assert result.degraded is True
+    assert result.candidates == ()
+    assert result.error is not None
+    assert result.error.cause == "index_not_loaded"
+
+
+def test_descriptor_fidelity_gate_rejects_large_optimized_delta() -> None:
+    # Arrange
+    retriever = LocalVprRetriever()
+
+    # Act
+    report = retriever.verify_descriptor_fidelity((1.0, 0.0), (0.0, 1.0), max_l2_delta=0.1)
+
+    # Assert
+    assert report.accepted is False
+    assert report.observed_l2_delta > report.max_l2_delta