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_sprint239_bounded_grb_acquisition.py

@@ -19,6 +19,7 @@ from app.models import Area, Dataset, Job, Project
 from app.schemas.grb import GrbAcquireRequest
 from app.services.dataset_service import DatasetService
 from app.services.grb_acquisition_service import GrbAcquisitionService
+from tests.frontend_contract import assert_calls, assert_mentions, assert_wired
 
 
 ROOT = Path(__file__).resolve().parents[2]
@@ -391,6 +392,7 @@ def test_grb_frontend_and_contracts_use_only_the_governed_backend_path() -> None
     assert "result[product.key] = null" in workspace
     assert ": onDemandThemeActive\n        ? null\n        : mapFeatureCollection" in workspace
     assert "onSetContextLayerLabel" in workspace
-    assert "'Automatisch'" in workspace
+    # GRB is acquired on demand through the governed backend path.
+    assert_wired(workspace, "officialMapProducts.grb")
     assert "/datasets/grb/acquire" in contracts
     assert "geo.api.vlaanderen.be" not in workspace