Hub-and-Spoke Umbau: Multi-Tenant Zentrale + Satellite-Agent

- Backend: Customer/Satellite Models, customer_id auf Server/Job/Audit
- Satellite-API: heartbeat, poll (atomares Claiming), logs, result,
  scan-result, health-report - Auth via X-Api-Key (SHA-256 gehasht)
- Job-Queue: pending/claimed/running/success/failed + Stale-Janitor
- Batch-Trigger: ein Job pro Server, Satellite arbeitet sequenziell ab
- Credentials bleiben lokal: nur symbolische credential_ref zentral
- Neues Paket satellite/: Pull-Loop, WinRM/SSH/CAU/Scanner, PyInstaller-tauglich
- Frontend: Kunden-Switcher, Satelliten-View, Polling statt WebSocket
- Entfernt: WebSocket/Socket.io, Redis, zentrale Credentials, JobRunner
- Docs: README/AGENTS/PROMPT auf neue Architektur aktualisiert

backend/app/schemas/server.py

@@ -8,13 +8,14 @@ from app.models.server import ServerType
 
 
 class ServerCreate(BaseModel):
+    customer_id: int
     name: str = Field(min_length=1, max_length=255)
     hostname: str = Field(min_length=1, max_length=255)
     port: int = 5985
     type: ServerType = ServerType.WINDOWS
     description: str | None = None
     tags: str | None = None
-    credential_id: int | None = None
+    credential_ref: str | None = None
 
 
 class ServerUpdate(BaseModel):
@@ -24,29 +25,24 @@ class ServerUpdate(BaseModel):
     type: ServerType | None = None
     description: str | None = None
     tags: str | None = None
-    credential_id: int | None = None
+    credential_ref: str | None = None
 
 
 class ServerRead(BaseModel):
     model_config = ConfigDict(from_attributes=True)
 
     id: int
+    customer_id: int
     name: str
     hostname: str
     port: int
     type: ServerType
     description: str | None
     tags: str | None
-    credential_id: int | None
+    credential_ref: str | None
     last_health_at: datetime | None
     last_health_ok: bool | None
+    last_health_message: str | None
+    discovered_by_scan: bool
     created_at: datetime
     updated_at: datetime
-
-
-class HealthCheckResult(BaseModel):
-    server_id: int
-    ok: bool
-    latency_ms: float | None = None
-    message: str
-    checked_at: datetime