fix(use-cases): Verifikations-Methode aus Primaer-Use-Case ableiten (Fallback)

Member-canonical_controls tragen meist kein evidence_type/verification_method
(wie schon source_citation). primary_verification_method() leitet die Methode
deterministisch aus dem Primaer-Use-Case ab (impressum->document,
code_security->source_code, ...). Populiert mc_verification beim naechsten Seed.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend-compliance/compliance/data/use_case_registry.py

@@ -369,6 +369,13 @@ def enabled_use_cases() -> list[UseCase]:
     return [uc for uc in _USE_CASES if uc.enabled]
 
 
+def primary_verification_method(use_case_key: str | None) -> str | None:
+    """Repraesentative Verifikations-Methode eines Use Case (erste deklarierte)
+    — deterministischer Fallback, wenn die MC-Member kein evidence_type tragen."""
+    uc = REGISTRY.get(use_case_key) if use_case_key else None
+    return uc.verification_methods[0] if uc and uc.verification_methods else None
+
+
 def seed_classify(
     scopes=(), categories=(), vmethods=(), etypes=(),
 ) -> tuple[list[str], str | None]:

backend-compliance/scripts/classify_mc_use_cases.py

@@ -107,7 +107,9 @@ async def run_seed(conn, limit: int = 0) -> dict:
                 mc_uuid, mc_id, uc, is_prim)
             n_uc += 1
         n_mc += 1
-        m = verif.get(mc_uuid)
+        # Verifikations-Methode: Member-evidence oder (Fallback) aus dem
+        # Primaer-Use-Case ableiten (Member tragen oft kein evidence_type).
+        m = verif.get(mc_uuid) or reg.primary_verification_method(uc_primary)
         if m:
             await conn.execute(
                 """INSERT INTO compliance.mc_verification