Add QA evidence map overlay

frontend/src/components/GeoMap.tsx

@@ -7,6 +7,7 @@ interface GeoMapProps {
   areaData?: GeoJSON.FeatureCollection | null
   selectedFeature?: GeoJSON.Feature | null
   selectionData?: GeoJSON.FeatureCollection | null
+  qaEvidenceData?: GeoJSON.FeatureCollection | null
   selectionBbox?: { min_x: number; min_y: number; max_x: number; max_y: number } | null
   bboxSelectionMode?: boolean
   visible?: boolean
@@ -97,6 +98,7 @@ function GeoMap({
   areaData = null,
   selectedFeature = null,
   selectionData = null,
+  qaEvidenceData = null,
   selectionBbox = null,
   bboxSelectionMode = false,
   visible = true,
@@ -148,7 +150,18 @@ function GeoMap({
         onMapCoordinateSelectRef.current?.([event.lngLat.lng, event.lngLat.lat])
         return
       }
-      const layers = ['dataset-fill', 'dataset-line', 'area-fill', 'area-line'].filter((layerId) => map.getLayer(layerId))
+      const layers = [
+        'qa-evidence-fill',
+        'qa-evidence-line',
+        'qa-evidence-circle',
+        'selection-result-fill',
+        'selection-result-line',
+        'selection-result-circle',
+        'dataset-fill',
+        'dataset-line',
+        'area-fill',
+        'area-line',
+      ].filter((layerId) => map.getLayer(layerId))
       if (layers.length === 0) {
         onFeatureSelectRef.current?.(null)
         return
@@ -463,6 +476,74 @@ function GeoMap({
     })
   }, [selectionData, mapStyleReady])
 
+  useEffect(() => {
+    const map = mapRef.current
+    if (!map || !mapStyleReady || !map.isStyleLoaded()) {
+      return
+    }
+
+    const evidenceCollection = qaEvidenceData ?? EMPTY_FEATURE_COLLECTION
+    if (map.getSource('qa-evidence')) {
+      ;(map.getSource('qa-evidence') as maplibregl.GeoJSONSource).setData(evidenceCollection)
+      return
+    }
+
+    map.addSource('qa-evidence', { type: 'geojson', data: evidenceCollection })
+    const evidenceColor = [
+      'match',
+      ['get', 'qa_evidence_role'],
+      'match_candidate',
+      '#2563eb',
+      'match_reference',
+      '#0f766e',
+      'false_positive',
+      '#dc2626',
+      'false_negative',
+      '#d97706',
+      '#475569',
+    ] as maplibregl.ExpressionSpecification
+    map.addLayer({
+      id: 'qa-evidence-fill',
+      type: 'fill',
+      source: 'qa-evidence',
+      filter: ['match', ['geometry-type'], ['Polygon', 'MultiPolygon'], true, false],
+      paint: {
+        'fill-color': evidenceColor,
+        'fill-opacity': 0.28,
+      },
+    })
+    map.addLayer({
+      id: 'qa-evidence-line',
+      type: 'line',
+      source: 'qa-evidence',
+      filter: ['match', ['geometry-type'], ['Polygon', 'MultiPolygon', 'LineString', 'MultiLineString'], true, false],
+      paint: {
+        'line-color': evidenceColor,
+        'line-width': [
+          'match',
+          ['get', 'qa_evidence_role'],
+          'false_positive',
+          4,
+          'false_negative',
+          4,
+          3,
+        ],
+      },
+    })
+    map.addLayer({
+      id: 'qa-evidence-circle',
+      type: 'circle',
+      source: 'qa-evidence',
+      filter: ['match', ['geometry-type'], ['Point', 'MultiPoint'], true, false],
+      paint: {
+        'circle-color': evidenceColor,
+        'circle-radius': 7,
+        'circle-stroke-color': '#ffffff',
+        'circle-stroke-width': 2,
+      },
+    })
+  }, [qaEvidenceData, mapStyleReady])
+
   return <div className="map-container" ref={containerRef} />
 }
 

frontend/src/components/map/MapWorkspace.tsx

@@ -176,6 +176,11 @@ interface MapWorkspaceProps {
   selectedMapAreaId: string
   areaFeatureCollection: GeoJSON.FeatureCollection | null
   mapFeatureCollection: GeoJSON.FeatureCollection | null
+  qualityEvidenceGeoJson?: GeoJSON.FeatureCollection | null
+  qualityEvidenceFeatureCount?: number
+  qualityEvidenceLoading?: boolean
+  qualityEvidenceError?: string | null
+  qualityEvidenceWarnings?: string[]
   mapLayerLabel: string
   mapLayerSourceLabel: string
   mapLayerProvenance: string
@@ -219,6 +224,7 @@ interface MapWorkspaceProps {
   onSelectMapQaReferenceDataset: (datasetId: string) => void
   onRunMapSelectionQa: () => void
   onOpenMapSelectionQualityEvidence: () => void
+  onClearQualityEvidence?: () => void
 }
 
 export function MapWorkspace({
@@ -226,6 +232,11 @@ export function MapWorkspace({
   selectedMapAreaId,
   areaFeatureCollection,
   mapFeatureCollection,
+  qualityEvidenceGeoJson = null,
+  qualityEvidenceFeatureCount = 0,
+  qualityEvidenceLoading = false,
+  qualityEvidenceError = null,
+  qualityEvidenceWarnings = [],
   mapLayerLabel,
   mapLayerSourceLabel,
   mapLayerProvenance,
@@ -269,6 +280,7 @@ export function MapWorkspace({
   onSelectMapQaReferenceDataset,
   onRunMapSelectionQa,
   onOpenMapSelectionQualityEvidence,
+  onClearQualityEvidence,
 }: MapWorkspaceProps): JSX.Element {
   const [bboxSelectionMode, setBboxSelectionMode] = useState(false)
   const [firstSelectionCorner, setFirstSelectionCorner] = useState<[number, number] | null>(null)
@@ -398,6 +410,11 @@ export function MapWorkspace({
           <strong>{mapFeatureCollection ? `${mapFeatureCount} rendered features` : 'No layer rendered'}</strong>
           <small>{mapLayerProvenance}</small>
         </div>
+        <div>
+          <span>QA/QC evidence</span>
+          <strong>{qualityEvidenceGeoJson ? `${qualityEvidenceFeatureCount} evidence features` : 'No evidence overlay'}</strong>
+          <small>{qualityEvidenceLoading ? 'Loading persisted evidence' : 'Matches, false positives and false negatives'}</small>
+        </div>
       </div>
 
       <div className="map-control-surface" aria-label="Map workspace controls">
@@ -483,9 +500,37 @@ export function MapWorkspace({
             <span>Draw state</span>
             <strong>{mapFeatureCollection ? `${mapFeatureCount} rendered features` : 'No active vector or result layer'}</strong>
           </div>
+          <div>
+            <span>QA evidence overlay</span>
+            <strong>{qualityEvidenceGeoJson ? `${qualityEvidenceFeatureCount} rendered` : 'off'}</strong>
+          </div>
         </div>
       </div>
 
+      {qualityEvidenceGeoJson || qualityEvidenceError || qualityEvidenceWarnings.length > 0 ? (
+        <div className="qa-evidence-map-status" aria-label="QA/QC evidence map overlay status">
+          <div>
+            <span>QA/QC evidence overlay</span>
+            <strong>{qualityEvidenceGeoJson ? `${qualityEvidenceFeatureCount} persisted features` : 'Not loaded'}</strong>
+            {qualityEvidenceError ? <p className="error">{qualityEvidenceError}</p> : null}
+            {qualityEvidenceWarnings.length > 0 ? (
+              <p className="muted">{qualityEvidenceWarnings.length} evidence id{qualityEvidenceWarnings.length === 1 ? '' : 's'} could not be resolved.</p>
+            ) : null}
+          </div>
+          <div className="qa-evidence-legend" aria-label="QA/QC evidence overlay legend">
+            <span><i className="qa-evidence-swatch qa-evidence-swatch-match-candidate" /> Match candidate</span>
+            <span><i className="qa-evidence-swatch qa-evidence-swatch-match-reference" /> Match reference</span>
+            <span><i className="qa-evidence-swatch qa-evidence-swatch-false-positive" /> False positive</span>
+            <span><i className="qa-evidence-swatch qa-evidence-swatch-false-negative" /> False negative</span>
+          </div>
+          {onClearQualityEvidence ? (
+            <button className="secondary-action" type="button" onClick={onClearQualityEvidence}>
+              Clear QA evidence
+            </button>
+          ) : null}
+        </div>
+      ) : null}
+
       {!mapFeatureCollection ? (
         <div className="empty-state map-empty-state">
           <strong>No active vector or result layer</strong>
@@ -514,6 +559,7 @@ export function MapWorkspace({
           areaData={areaFeatureCollection}
           selectedFeature={selectedFeature}
           selectionData={mapSelectionResult?.geojson ?? null}
+          qaEvidenceData={qualityEvidenceGeoJson}
           selectionBbox={mapSelectionBbox}
           bboxSelectionMode={bboxSelectionMode}
           visible={mapLayerVisible}

frontend/src/components/quality/QualityResultsPanel.tsx

@@ -17,6 +17,9 @@ interface QualityResultsPanelProps {
   candidateDatasets: DatasetCreateResponse[]
   referenceDatasets: DatasetCreateResponse[]
   onRefresh: () => void
+  onOpenEvidenceMap?: (qualityCheckId: string) => void
+  evidenceLoading?: boolean
+  evidenceError?: string | null
 }
 
 function qualityMetricLabel(metricKey: string): string {
@@ -95,6 +98,9 @@ export function QualityResultsPanel({
   candidateDatasets,
   referenceDatasets,
   onRefresh,
+  onOpenEvidenceMap,
+  evidenceLoading = false,
+  evidenceError = null,
 }: QualityResultsPanelProps): JSX.Element {
   const [showAllQualityChecks, setShowAllQualityChecks] = useState(false)
   const [qualityStatusFilter, setQualityStatusFilter] = useState('all')
@@ -204,7 +210,21 @@ export function QualityResultsPanel({
             >
               Inspect latest check
             </button>
+            <button
+              type="button"
+              className="secondary-action"
+              onClick={() => latestCheck?.id && onOpenEvidenceMap?.(latestCheck.id)}
+              disabled={!latestCheck || evidenceLoading || !onOpenEvidenceMap}
+            >
+              {evidenceLoading ? 'Loading map evidence...' : 'Show latest on map'}
+            </button>
           </div>
+          {evidenceError ? (
+            <div className="result-state result-state-error">
+              <strong>QA/QC evidence overlay could not be loaded.</strong>
+              <p>{evidenceError}</p>
+            </div>
+          ) : null}
           {selectedQualityCheck ? (
             <>
               <div className="quality-drilldown-grid">
@@ -254,6 +274,14 @@ export function QualityResultsPanel({
                   <span>Map evidence handoff</span>
                   <strong>{selectedCandidateName} / {selectedReferenceName}</strong>
                   <p>Use the candidate and reference datasets as map layers for spatial review.</p>
+                  <button
+                    type="button"
+                    className="secondary-action"
+                    onClick={() => onOpenEvidenceMap?.(selectedQualityCheck.id)}
+                    disabled={evidenceLoading || !onOpenEvidenceMap}
+                  >
+                    {evidenceLoading ? 'Loading overlay...' : 'Show evidence overlay'}
+                  </button>
                 </div>
               </div>
               <div className="quality-feature-evidence-grid" aria-label="Feature-level QA/QC evidence">
@@ -440,6 +468,14 @@ export function QualityResultsPanel({
                   <button type="button" className="secondary-action" onClick={() => setSelectedQualityCheckId(check.id)}>
                     Inspect check
                   </button>
+                  <button
+                    type="button"
+                    className="secondary-action"
+                    onClick={() => onOpenEvidenceMap?.(check.id)}
+                    disabled={evidenceLoading || !onOpenEvidenceMap}
+                  >
+                    Show evidence on map
+                  </button>
                 </div>
                 <div className="quality-score-row">
                   <div>