Polish live workbench shell layout

backend/tests/test_sprint53_selection_ergonomics.py

@@ -27,6 +27,18 @@ def test_data_workspace_keeps_catalog_wide_enough_for_populated_state() -> None:
     assert ".dataset-card .button-row" in css
 
 
+def test_shell_preserves_workspace_width_on_standard_desktop_viewports() -> None:
+    css = (ROOT / "frontend" / "src" / "styles" / "app.css").read_text(encoding="utf-8")
+    app = (ROOT / "frontend" / "src" / "App.tsx").read_text(encoding="utf-8")
+
+    assert "grid-template-columns: 12.5rem minmax(0, 1fr) 21rem" in css
+    assert "@media (max-width: 1360px)" in css
+    assert ".workbench-inspector {\n    grid-column: 1 / -1;" in css
+    assert "height: auto;" in css
+    assert "window.scrollTo({ top: 0, left: 0 })" in app
+    assert "}, [activeWorkspace])" in app
+
+
 def test_app_wires_dataset_quick_actions_to_existing_workspaces() -> None:
     app = (ROOT / "frontend" / "src" / "App.tsx").read_text(encoding="utf-8")