From c97cb5bdd31e32af07b2d3b641c7a3fd6696aa35 Mon Sep 17 00:00:00 2001
From: Codex <codex@geointel.local>
Date: Sun, 19 Jul 2026 02:21:06 +0200
Subject: [PATCH] Center map on selected work area

---
 CHANGELOG.md                                             | 3 +++
 .../test_sprint186_map_first_geographic_explorer.py      | 2 ++
 docs/CODEX_EXECUTION_LOG.md                              | 3 +++
 frontend/src/components/GeoMap.tsx                       | 9 +++++++--
 4 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 509ddceb..3ec7ea2b 100644
--- a/CHANGELOG.md
+++ b/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)
 
diff --git a/backend/tests/test_sprint186_map_first_geographic_explorer.py b/backend/tests/test_sprint186_map_first_geographic_explorer.py
index d77019e4..9132787a 100644
--- a/backend/tests/test_sprint186_map_first_geographic_explorer.py
+++ b/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
diff --git a/docs/CODEX_EXECUTION_LOG.md b/docs/CODEX_EXECUTION_LOG.md
index be3ee9f1..05c0bda3 100644
--- a/docs/CODEX_EXECUTION_LOG.md
+++ b/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.
 
diff --git a/frontend/src/components/GeoMap.tsx b/frontend/src/components/GeoMap.tsx
index a31aa7cb..409b45aa 100644
--- a/frontend/src/components/GeoMap.tsx
+++ b/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) {