feat: add governed agricultural parcel history

frontend/src/components/datasets/SourceCatalogPanel.tsx

@@ -9,6 +9,7 @@ const THEME_LABELS: Record<string, string> = {
   population: 'Bevolking',
   forest: 'Bos',
   nature_value: 'Natuurwaarde',
+  agriculture: 'Landbouw',
   water: 'Water',
   roads: 'Wegen en transport',
   parcels: 'Percelen',
@@ -105,10 +106,14 @@ export function SourceCatalogPanel({ datasets }: SourceCatalogPanelProps): JSX.E
       String(dataset.source_metadata?.['product_key'] ?? 'most_recent') !== 'most_recent',
   )
   const bwkDatasets = ready.filter((dataset) => dataset.source_name === 'inbo_bwk_natura2000')
+  const agricultureDatasets = ready.filter((dataset) => dataset.source_name === 'agentschap_landbouw_zeevisserij_agricultural_parcels')
+  const agricultureYears = agricultureDatasets
+    .flatMap((dataset) => dataset.observed_at ? [new Date(dataset.observed_at).getUTCFullYear()] : [])
   const pendingSources = AVAILABLE_SOURCES.filter((source) => {
     if (source.key === 'waterinfo') return waterinfoDatasets.length === 0
     if (source.key === 'historical_orthophoto') return historicalOrthophotos.length === 0
     if (source.key === 'bwk') return bwkDatasets.length === 0
+    if (source.key === 'agriculture') return agricultureDatasets.length === 0
     return true
   })
   const themes = Object.keys(THEME_LABELS).map((theme) => {
@@ -168,7 +173,7 @@ export function SourceCatalogPanel({ datasets }: SourceCatalogPanelProps): JSX.E
         ))}
       </div>
 
-      {waterinfoDatasets.length > 0 || historicalOrthophotos.length > 0 || bwkDatasets.length > 0 ? (
+      {waterinfoDatasets.length > 0 || historicalOrthophotos.length > 0 || bwkDatasets.length > 0 || agricultureDatasets.length > 0 ? (
         <div className="source-catalog-loaded" aria-label="Aanvullende ingeladen bronnen">
           {waterinfoDatasets.length > 0 ? (
             <article>
@@ -191,6 +196,13 @@ export function SourceCatalogPanel({ datasets }: SourceCatalogPanelProps): JSX.E
               <p>Biologische waardering en habitataandelen blijven afzonderlijke, brongetrouwe metingen met herkomstinformatie.</p>
             </article>
           ) : null}
+          {agricultureDatasets.length > 0 ? (
+            <article>
+              <strong>Landbouwgebruikspercelen</strong>
+              <span>{agricultureDatasets.length} definitieve jaargangen{agricultureYears.length ? ` · ${Math.min(...agricultureYears)}-${Math.max(...agricultureYears)}` : ''}</span>
+              <p>Oppervlakte en officiele hoofdteeltgroepen zijn historisch vergelijkbaar; perceelidentiteiten blijven bewust niet gekoppeld tussen jaren.</p>
+            </article>
+          ) : null}
         </div>
       ) : null}