feat(scan): whiten receipt backgrounds and embed OCR in PDFs

backend/src/routes/instanceAgents.ts

@@ -152,6 +152,7 @@ export default async function instanceAgentRoutes(server: FastifyInstance) {
                 active: instanceAgents.active,
                 preferredScannerName: instanceAgents.preferredScannerName,
                 scanDefaults: instanceAgents.scanDefaults,
+                capabilities: instanceAgents.capabilities,
             })
             .from(instanceAgents)
             .where(eq(instanceAgents.id, body.agentId))
@@ -161,6 +162,14 @@ export default async function instanceAgentRoutes(server: FastifyInstance) {
             return reply.code(404).send({ error: "Active agent not found" })
         }
 
+        const settings = { ...((agent.scanDefaults || {}) as Record<string, any>), ...(body.settings || {}) }
+        const enabled = (value: unknown) => value === true || (typeof value === "string" && ["1", "true", "yes", "ja", "on"].includes(value.toLowerCase().trim()))
+        const capabilities = agent.capabilities as Record<string, any>
+        if (((settings.format || "pdf") === "pdf" && enabled(settings.ocr) && !capabilities?.ocr) ||
+            (enabled(settings.backgroundCleanup) && !capabilities?.backgroundCleanup)) {
+            return reply.code(409).send({ error: "Bitte den Scanner-Agenten mit Tesseract und OpenCV aktualisieren. Die angeforderte Scan-Verarbeitung ist dort noch nicht verfügbar." })
+        }
+
         const [job] = await server.db
             .insert(instanceAgentScanJobs)
             .values({
@@ -169,10 +178,7 @@ export default async function instanceAgentRoutes(server: FastifyInstance) {
                 requestedBy: req.user?.user_id,
                 scannerName: body.scannerName || agent.preferredScannerName,
                 requestedFilename: body.requestedFilename,
-                settings: {
-                    ...((agent.scanDefaults || {}) as Record<string, any>),
-                    ...(body.settings || {}),
-                },
+                settings,
                 target: body.target || {},
             })
             .returning()