feat(documents): prepare inbox suggestions and add entity assignments

backend/src/modules/scanner-inbox.worker.ts

@@ -0,0 +1,27 @@
+import type { FastifyInstance } from "fastify"
+import { createScannerInboxService, type ScannerInboxService } from "./scanner-inbox.service"
+
+export function startScannerInboxWorker(server: FastifyInstance, service: Pick<ScannerInboxService, "processNextSuggestion"> = createScannerInboxService(server.db)) {
+    let stopped = false
+    let timer: ReturnType<typeof setTimeout> | undefined
+    let running: Promise<void> | undefined
+    const run = async () => {
+        try {
+            // One analysis per process; database claims coordinate multiple backend instances.
+            while (!stopped && await service.processNextSuggestion()) { /* drain the durable queue */ }
+        } catch {
+            server.log.error("KI-Vorbereitung der Dokumentenablage unterbrochen; erneuter Versuch folgt.")
+        } finally {
+            if (!stopped) {
+                timer = setTimeout(() => { running = run() }, 2000)
+                timer.unref()
+            }
+        }
+    }
+    server.addHook("onReady", async () => { running = run() })
+    server.addHook("onClose", async () => {
+        stopped = true
+        clearTimeout(timer)
+        await running
+    })
+}