Add bounded Flanders thematic analysis

frontend/README.md

@@ -71,6 +71,15 @@ but is not required for the primary choose-theme, draw-area, read-result flow.
 
 The primary workflow is deliberately short: choose a municipality or the complete region, choose a data theme, drag a rectangle on the MapLibre map and read the resulting PostGIS evidence. Releasing the drag runs the active theme query and every other available theme query for the same EPSG:4326 bbox. The active `area_id` constrains every drawn/manual selection to `bbox ∩ Area`; `Volledig werkgebied` uses a bbox enclosing the Area and therefore resolves to the exact persisted geometry. The result panel shows selection area, exact intersection totals, active-theme density, source identity and bounded feature properties. Map rendering remains capped at 1,000 features while `total_feature_count` reports the exact database count.
 
+In the Flanders workbench, ruimtebeslag, open ruimte, population density,
+node value and service level may appear as `Op aanvraag`. Drawing a rectangle
+or choosing a municipality uses the existing backend Job/Dataset flow to
+acquire and persist those five official rasters for the exact selection, then
+shows all available semantic metrics together. Identical requests reuse the
+persisted artifact. The complete Flanders Area is deliberately unavailable for
+these rasters because it exceeds the backend safety ceiling; this does not
+limit vector or partitioned bathymetry analysis of the complete region.
+
 Detection Lab only lists ready imagery rasters. Governed height, flood-hazard
 and thematic policy rasters remain available in the map explorer but are
 excluded from the `Luchtbeeld` selector.
@@ -92,7 +101,13 @@ local YOLO model, Detection persistence and automatic QA against ready GRB
 buildings. The panel shows all stages and errors; successful detections open as
 an explicit AI-result overlay. Rectangles must be 128-1,024 m per side.
 
-The theme catalog currently recognizes buildings, population, forest/green, water, roads and parcels from dataset names and canonical `reference_layer_name` metadata. A theme is enabled only when a ready persisted vector dataset exists; otherwise it states `Bron nog niet ingeladen`. This prevents missing population or land-cover sources from appearing as zero-valued observations. The previous technical Map workspace remains available through `Geavanceerde werkbank` for derived datasets, QA/QC evidence and export operations.
+The theme catalog recognizes the governed vector, raster and partitioned
+sources through canonical source metadata. A theme is enabled only when a
+ready persisted Dataset exists, except for the five allowlisted Flanders
+policy rasters that explicitly show `Op aanvraag`. Other missing themes state
+`Bron nog niet ingeladen`; they never appear as zero-valued observations. The
+technical Map workspace remains available through `Geavanceerde werkbank` for
+derived datasets, QA/QC evidence and export operations.
 
 The workbench uses a task-based shell instead of a single long panel stack. `App.tsx` still owns shared orchestration state, but Map is the default product entry and Overview, Data, QA/QC, AI Labs, Exports and System remain secondary workspaces with a persistent top context bar and an optional selection-detail drawer.