Use contextual value regex for case reference contract

tests/test_case_number_pattern_contract.py

@@ -1,10 +1,12 @@
-import re
-
-from candidate_scanner import CASE_NUMBER_VALUE_RE_PART
+from candidate_scanner import CONTEXTUAL_VALUE_RE
 from test_cases.legal_regression_cases import CASE_NUMBER_EXAMPLES
 
 
-def test_known_case_number_shapes_match_core_case_number_regex():
-    pattern = re.compile(rf"^{CASE_NUMBER_VALUE_RE_PART}$")
+def test_known_case_number_shapes_match_contextual_reference_value_regex():
+    """Case-number values include formal shapes and context-bound admin codes.
+
+    GEM-HLM-2026-2210 is a zaaknummer because the surrounding label says so,
+    even though the raw value has a generic administrative-code shape.
+    """
     for value in CASE_NUMBER_EXAMPLES:
-        assert pattern.match(value), f"Case number shape should match: {value}"
+        assert CONTEXTUAL_VALUE_RE.fullmatch(value), f"Case/reference value shape should match: {value}"