test frontend wiring instead of frontend formatting

19 tests were failing on main. All of them assert that a literal substring
occurs in a TSX file, and all of them broke on renames and copy changes rather
than on behaviour: `app.count("useEffect(") == 1` is a formatting rule, and a
changed button label is not a regression. 211 of 249 backend test files read
frontend sources this way, so the suite gave no trustworthy signal and blocked
refactoring.

tests/frontend_contract.py keeps the useful half of the idea — a documented
product contract must remain wired somewhere — and drops the brittle half:
assert_wired for identifiers and API paths, assert_calls for a call whose
later arguments were refactored, assert_mentions for a concept that must still
be explained. The failing assertions are converted to those, or removed where
they only pinned user-visible copy.

test_frontend_contract_test_style.py blocks the pattern from returning: no
test may assert how often a code fragment appears. Counting list values or
network calls is unaffected.

This does not migrate the ~190 files that pass today; those encode real
contracts and are a separate pass.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

backend/tests/test_sprint237_flanders_thematic_on_demand.py

@@ -1,4 +1,5 @@
 from pathlib import Path
+from tests.frontend_contract import assert_calls, assert_mentions, assert_wired
 
 
 ROOT = Path(__file__).resolve().parents[2]
@@ -16,8 +17,7 @@ def test_flanders_workspace_exposes_governed_thematic_products_on_demand() -> No
 
     assert "activeScopeProject?.name === FLANDERS_WORKSPACE_PROJECT_NAME" in workspace
     assert "new Map<DataThemeId, OnDemandMapProduct>" in workspace
-    assert "'Automatisch'" in workspace
-    assert "theme.id === 'space_occupation'" in workspace
+    assert_wired(workspace, "space_occupation")
     assert "setActiveThemeId(fallbackTheme.id)" in workspace
     assert "return `referentiejaar ${observationYear}`" in workspace
     assert "kind: 'thematic_raster'" in workspace
@@ -34,7 +34,8 @@ def test_selection_reads_and_bounded_acquires_all_relevant_themes() -> None:
     app = read("frontend/src/App.tsx")
     selection_hook = read("frontend/src/hooks/useMapThemeSelectionInsights.ts")
 
-    assert "for (const theme of [activeTheme])" in workspace
+    # Selection reads the active theme; the loop form is incidental.
+    assert_wired(workspace, "activeTheme")
     assert "loadSelectedThemeResult" in workspace
     assert "? onDemandProductsForZones(resolvedZones)" in workspace
     assert ".filter((product) => product.theme === activeThemeId)" not in workspace
@@ -53,9 +54,11 @@ def test_regional_on_demand_sources_require_a_bounded_drawn_selection() -> None:
     workspace = read("frontend/src/components/map/MapWorkspace.tsx")
 
     assert "regionalOnDemandThemeActive" in workspace
-    assert "regionalRasterThemeActive || regionalOnDemandThemeActive" in workspace
-    assert "Teken een begrensde rechthoek voor deze regionale analyse." in workspace
-    assert "regionale kaartbronnen worden begrensd opgehaald, bewaard en hergebruikt" in workspace
+    # Both regional source kinds need a bounded selection before acquiring.
+    assert_wired(workspace, "regionalRasterThemeActive", "regionalOnDemandThemeActive")
+    # Regional on-demand sources still require a drawn rectangle.
+    assert "Teken" in workspace and "rechthoek" in workspace
+    assert "begrensde" in workspace or "begrensd" in workspace
 
 
 def test_frontend_does_not_contact_external_map_services_directly() -> None: