feat: Package 4 Nachbesserungen — History-Tracking, Pagination, Frontend-Fixes

Backend:
- Migration 009: compliance_einwilligungen_consent_history Tabelle
- EinwilligungenConsentHistoryDB Modell (consent_id, action, version, ip, ua, source)
- _record_history() Helper: automatisch bei POST /consents (granted) + PUT /revoke (revoked)
- GET /consents/{id}/history Endpoint (vor revoke platziert für korrektes Routing)
- GET /consents: history-Array pro Eintrag (inline Sub-Query)
- 5 neue Tests (TestConsentHistoryTracking) — 32/32 bestanden

Frontend:
- consent/route.ts: limit+offset aus Frontend-Request weitergeleitet, total-Feld ergänzt
- Neuer Proxy consent/[id]/history/route.ts für GET /consents/{id}/history
- page.tsx: globalStats state + loadStats() (Backend /consents/stats für globale Zahlen)
- page.tsx: Stats-Kacheln auf globalStats umgestellt (nicht mehr page-relativ)
- page.tsx: history-Mapper: created_at→timestamp, consent_version→version
- page.tsx: loadStats() bei Mount + nach Revoke

Dokumentation:
- Developer Portal: neue API-Docs-Seite /api/einwilligungen (Consent + Legal Docs + Cookie Banner)
- developer-portal/app/api/page.tsx: Consent Management Abschnitt
- MkDocs: History-Endpoint, Pagination-Abschnitt, History-Tracking Abschnitt
- Deploy-Skript: scripts/apply_consent_history_migration.sh

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend-compliance/compliance/api/einwilligungen_routes.py

@@ -28,6 +28,7 @@ from ..db.einwilligungen_models import (
     EinwilligungenCompanyDB,
     EinwilligungenCookiesDB,
     EinwilligungenConsentDB,
+    EinwilligungenConsentHistoryDB,
 )
 
 logger = logging.getLogger(__name__)
@@ -72,6 +73,20 @@ def _get_tenant(x_tenant_id: Optional[str] = Header(None, alias='X-Tenant-ID'))
     return x_tenant_id
 
 
+def _record_history(db: Session, consent: EinwilligungenConsentDB, action: str) -> None:
+    """Protokolliert eine Aenderung an einer Einwilligung in der History-Tabelle."""
+    entry = EinwilligungenConsentHistoryDB(
+        consent_id=consent.id,
+        tenant_id=consent.tenant_id,
+        action=action,
+        consent_version=consent.consent_version,
+        ip_address=consent.ip_address,
+        user_agent=consent.user_agent,
+        source=consent.source,
+    )
+    db.add(entry)
+
+
 # ============================================================================
 # Catalog
 # ============================================================================
@@ -326,6 +341,21 @@ async def list_consents(
                 "ip_address": c.ip_address,
                 "user_agent": c.user_agent,
                 "created_at": c.created_at,
+                "history": [
+                    {
+                        "id": str(h.id),
+                        "action": h.action,
+                        "consent_version": h.consent_version,
+                        "ip_address": h.ip_address,
+                        "user_agent": h.user_agent,
+                        "source": h.source,
+                        "created_at": h.created_at,
+                    }
+                    for h in db.query(EinwilligungenConsentHistoryDB)
+                    .filter(EinwilligungenConsentHistoryDB.consent_id == c.id)
+                    .order_by(EinwilligungenConsentHistoryDB.created_at.asc())
+                    .all()
+                ],
             }
             for c in consents
         ],
@@ -351,6 +381,7 @@ async def create_consent(
         user_agent=request.user_agent,
     )
     db.add(consent)
+    _record_history(db, consent, 'granted')
     db.commit()
     db.refresh(consent)
 
@@ -364,6 +395,37 @@ async def create_consent(
     }
 
 
+@router.get("/consents/{consent_id}/history")
+async def get_consent_history(
+    consent_id: str,
+    tenant_id: str = Depends(_get_tenant),
+    db: Session = Depends(get_db),
+):
+    """Get the change history for a specific consent record."""
+    entries = (
+        db.query(EinwilligungenConsentHistoryDB)
+        .filter(
+            EinwilligungenConsentHistoryDB.consent_id == consent_id,
+            EinwilligungenConsentHistoryDB.tenant_id == tenant_id,
+        )
+        .order_by(EinwilligungenConsentHistoryDB.created_at.asc())
+        .all()
+    )
+    return [
+        {
+            "id": str(e.id),
+            "consent_id": str(e.consent_id),
+            "action": e.action,
+            "consent_version": e.consent_version,
+            "ip_address": e.ip_address,
+            "user_agent": e.user_agent,
+            "source": e.source,
+            "created_at": e.created_at,
+        }
+        for e in entries
+    ]
+
+
 @router.put("/consents/{consent_id}/revoke")
 async def revoke_consent(
     consent_id: str,
@@ -382,6 +444,7 @@ async def revoke_consent(
         raise HTTPException(status_code=400, detail="Consent is already revoked")
 
     consent.revoked_at = datetime.utcnow()
+    _record_history(db, consent, 'revoked')
     db.commit()
     db.refresh(consent)