feat: 7 Analyse-Module auf 100% — Backend-Endpoints, DB-Model, Frontend-Persistenz

Alle 7 Analyse-Module (Requirements → Report) von ~80% auf 100% gebracht:
- Modul 1 (Requirements): POST/DELETE Endpoints + Frontend-Anbindung + Rollback
- Modul 2 (Controls): Evidence-Linking UI mit Validity-Badge
- Modul 3 (Evidence): Pagination (Frontend + Backend)
- Modul 4 (Risk Matrix): Mitigation-UI, Residual Risk, Status-Workflow
- Modul 5 (AI Act): AISystemDB Model, 6 CRUD-Endpoints, Backend-Persistenz
- Modul 6 (Audit Checklist): PDF-Download + Session-History
- Modul 7 (Audit Report): Detail-Seite mit Checklist Sign-Off + Navigation

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

backend-compliance/compliance/api/schemas.py

@@ -385,6 +385,52 @@ class RiskMatrixResponse(BaseModel):
     risks: List[RiskResponse]
 
 
+# ============================================================================
+# AI System Schemas (AI Act Compliance)
+# ============================================================================
+
+class AISystemBase(BaseModel):
+    name: str
+    description: Optional[str] = None
+    purpose: Optional[str] = None
+    sector: Optional[str] = None
+    classification: str = "unclassified"
+    status: str = "draft"
+    obligations: Optional[List[str]] = None
+
+
+class AISystemCreate(AISystemBase):
+    pass
+
+
+class AISystemUpdate(BaseModel):
+    name: Optional[str] = None
+    description: Optional[str] = None
+    purpose: Optional[str] = None
+    sector: Optional[str] = None
+    classification: Optional[str] = None
+    status: Optional[str] = None
+    obligations: Optional[List[str]] = None
+
+
+class AISystemResponse(AISystemBase):
+    id: str
+    assessment_date: Optional[datetime] = None
+    assessment_result: Optional[Dict[str, Any]] = None
+    risk_factors: Optional[List[Dict[str, Any]]] = None
+    recommendations: Optional[List[str]] = None
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        from_attributes = True
+
+
+class AISystemListResponse(BaseModel):
+    systems: List[AISystemResponse]
+    total: int
+
+
 # ============================================================================
 # Dashboard & Export Schemas
 # ============================================================================