fix(consent-history): banner_provider als Fallback fürs CMP (#62)

Storage-Keys fehlen in Phase A (vor Consent) oft → provider blieb leer. Jetzt
fällt detect_consent_history auf den bereits aus dem Banner-DOM erkannten
banner_provider zurück → korrekter Anbieter + history_capable auch ohne
Storage-Eintrag.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

consent-tester/services/consent_history.py

@@ -53,9 +53,11 @@ def _is_versioned(provider: str, stored_value: Optional[str]) -> bool:
     return any(t in low for t in ("version", "consents", "timestamp", "consentid"))
 
 
-async def detect_consent_history(page: Any) -> dict:
+async def detect_consent_history(page: Any, banner_provider: str = "") -> dict:
     """Liest Storage/Cookies + DOM und liefert:
-    {provider, stored, versioned_consent, history_capable, withdraw_ui}."""
+    {provider, stored, versioned_consent, history_capable, withdraw_ui}.
+    `banner_provider` = bereits aus dem Banner-DOM erkanntes CMP — wird als
+    Fallback genutzt, da Storage-Keys in Phase A (vor Consent) oft noch fehlen."""
     keys: list[str] = []
     try:
         keys = await page.evaluate("() => Object.keys(window.localStorage || {})")
@@ -67,7 +69,9 @@ async def detect_consent_history(page: Any) -> dict:
     except Exception:
         cookie_names = []
 
-    provider = classify_provider(list(keys) + cookie_names)
+    # Provider zuerst aus Storage/Cookies, sonst aus dem erkannten Banner-CMP.
+    provider = (classify_provider(list(keys) + cookie_names)
+                or classify_provider([banner_provider or ""]))
 
     stored_value = None
     if provider == "Borlabs":