Add QA evidence map overlay

docs/API_CONTRACTS.md

@@ -1060,6 +1060,58 @@ Response:
 }
 ```
 
+### GET `/api/v1/projects/{project_id}/quality-checks/{quality_check_id}/evidence/geojson`
+
+Returns a canonical envelope containing a read-only QA/QC evidence overlay for a
+persisted quality check. The endpoint reads feature ids from
+`quality_checks.findings_json.match_evidence`,
+`false_positive_evidence` and `false_negative_evidence`, resolves them against
+persisted candidate/reference geometries and returns a GeoJSON FeatureCollection.
+
+Supported resolution paths:
+
+- dataset QA candidate/reference geometries from `vector_features`;
+- detection QA candidate geometries from persisted `detections`;
+- segmentation QA candidate geometries from persisted `segmentations`;
+- reference geometries from persisted `vector_features`.
+
+Response:
+
+```json
+{
+  "data": {
+    "quality_check_id": "uuid",
+    "project_id": "uuid",
+    "candidate_dataset_id": "uuid-or-null",
+    "reference_dataset_id": "uuid",
+    "analysis_run_id": "uuid-or-null",
+    "feature_count": 4,
+    "warnings": [],
+    "geojson": {
+      "type": "FeatureCollection",
+      "features": [
+        {
+          "type": "Feature",
+          "id": "match_candidate:feature-id",
+          "geometry": {},
+          "properties": {
+            "qa_evidence_role": "match_candidate",
+            "quality_check_id": "uuid",
+            "candidate_feature_id": "candidate-feature-id",
+            "reference_feature_id": "reference-feature-id",
+            "iou": 0.83
+          }
+        }
+      ]
+    }
+  }
+}
+```
+
+`qa_evidence_role` is one of `match_candidate`, `match_reference`,
+`false_positive` or `false_negative`. Missing persisted feature ids are reported
+in `warnings`; no fake geometries are produced.
+
 ## Exports
 
 ### POST `/api/v1/exports/geojson`

docs/CODEX_EXECUTION_LOG.md

@@ -1,3 +1,39 @@
+## Sprint 112 QA evidence map overlay (2026-06-25)
+
+Changed:
+- Added `QualityEvidenceService` to resolve persisted QA/QC evidence ids back to stored geometries.
+- Added `GET /api/v1/projects/{project_id}/quality-checks/{quality_check_id}/evidence/geojson`.
+- The endpoint returns a canonical envelope with `quality_check_id`, dataset/run provenance, warnings and a GeoJSON FeatureCollection.
+- Evidence resolution supports candidate dataset `vector_features`, candidate persisted `detections`/`segmentations` for analysis-run QA, and reference `vector_features`.
+- Added QA/QC panel actions to show selected or latest evidence on the Map workspace.
+- Added a MapLibre QA evidence source/layers with distinct match candidate, match reference, false-positive and false-negative styling.
+- Added map overlay loading/error/clear state and a compact legend.
+- Updated `docs/API_CONTRACTS.md`, `frontend/README.md`, `CHANGELOG.md` and `docs/TODO.md`.
+- Added regression coverage in `backend/tests/test_sprint112_qa_evidence_overlay.py`.
+
+Validation:
+- RED: `python -m pytest backend\tests\test_sprint112_qa_evidence_overlay.py -q` failed before implementation because `app.services.quality_evidence_service` did not exist.
+- RED: after backend implementation, the same test failed until frontend `qaEvidenceData`/API wiring existed.
+- `python -m pytest backend\tests\test_sprint112_qa_evidence_overlay.py -q` passed: 4 tests.
+- `cd frontend && npm run typecheck` passed after making the MapLibre expression type explicit.
+- `python -m pytest backend\tests\test_sprint112_qa_evidence_overlay.py backend\tests\test_qa_service.py backend\tests\test_sprint8c_detection_visualization_qa.py backend\tests\test_sprint9_segmentation_foundation.py -q` passed: 25 tests.
+- `python -m compileall backend/app` passed.
+- `cd backend && python -m pytest -q` passed: 356 tests.
+- `cd frontend && npm run typecheck` passed.
+- `cd frontend && npm run build` passed.
+- `cd backend && python -m alembic heads` passed: `202606120900 (head)`.
+- `cd backend && python -m alembic upgrade head --sql` passed.
+- `bash -n scripts/live_migration_smoke.sh` passed.
+- `bash scripts/run_readiness_check.sh` passed: 356 backend tests plus frontend typecheck/build.
+
+Limitations:
+- The overlay is generated read-only from existing persisted evidence and geometries; no new evidence table or migration was introduced.
+- Missing evidence ids are reported as warnings and do not create fake geometries.
+- No provider fetching, AI dependency, real model behavior or new product domain was added.
+
+Next recommended pass:
+- Add live browser validation for the QA evidence overlay against the deployed demo workflow, then consider a small export/handoff action for the evidence overlay GeoJSON.
+
 ## Sprint 111 QA feature evidence persistence (2026-06-25)
 
 Changed:

docs/TODO.md

@@ -378,3 +378,4 @@ This file now starts with the current implementation status. Older preparation/b
 - [x] Add Map workspace QA/QC shortcut for saved derived selection datasets.
 - [x] Add Map workspace QA/QC evidence drilldown handoff for saved selection comparisons.
 - [x] Persist QA/QC feature-level evidence for matches, false positives and false negatives.
+- [x] Render persisted QA/QC feature-level evidence as Map workspace overlays.