Center map on selected work area

CHANGELOG.md

@@ -38,6 +38,9 @@
   the workbench, so national Statbel 2025 population data is no longer
   mislabeled as a 2019 thematic raster. Selection-bounded SPW/UrbIS results
   remain available through the exact on-demand acquisition path.
+- Made a changed work area take viewport priority over a complete national
+  layer, so switching between Belgium, Wallonia, Brussels and the North Sea
+  visibly centers the map on the selected geography.
 
 ## Autonomous Belgium and North Sea RC program (2026-07-17)
 

backend/tests/test_sprint186_map_first_geographic_explorer.py

@@ -48,6 +48,8 @@ def test_map_rectangle_drag_is_wired_to_automatic_analysis() -> None:
     assert "resizeObserver.observe(containerRef.current)" in geomap
     assert "fitDataOnChangeRef.current" in geomap
     assert "map.fitBounds(bounds, { padding: 40, duration: 0 })" in geomap
+    assert "const areaChanged = lastFittedAreaRef.current !== areaData" in geomap
+    assert "areaChanged && areaData" in geomap
     assert "resizeObserver.disconnect()" in geomap
     assert ".workbench-main .geo-map-canvas .map-container" in styles
     assert "position: absolute;" in styles

docs/CODEX_EXECUTION_LOG.md

@@ -44,6 +44,9 @@
   on-demand placeholders. National Statbel 2025 population is now presented
   as the active source, while selection-bounded PICC/UrbIS acquisitions remain
   available only through an exact bounded request.
+- Live browser verification found that a changed work area was fitted together
+  with the complete active national layer. Area changes now fit the selected
+  geography first; subsequent layer changes retain the existing fit behavior.
 - Focused backend and frontend suites passed before full release validation;
   full local and Tower evidence follows in the final P5 gate.
 

frontend/src/components/GeoMap.tsx

@@ -500,8 +500,13 @@ function GeoMap({
       )
     }
 
-    const activeCollection = fitDataOnChange ? mergeFeatureCollections([areaData, data]) : areaData
-    const shouldFitArea = fitDataOnChange || lastFittedAreaRef.current !== areaData
+    const areaChanged = lastFittedAreaRef.current !== areaData
+    const activeCollection = areaChanged && areaData
+      ? areaData
+      : fitDataOnChange
+        ? mergeFeatureCollections([areaData, data])
+        : areaData
+    const shouldFitArea = fitDataOnChange || areaChanged
     if (activeCollection && shouldFitArea) {
       const bounds = collectCoordinates(activeCollection)
       if (bounds) {