feat: implement manual user validation and user deletion flow

src/services/businessCentral.ts

@@ -37,6 +37,8 @@ export interface BCSyncPreviewSection {
   writeUrlTemplate: string | null;
   writeBodyTemplate: string | null;
   canApply: boolean;
+  supported?: boolean;
+  supportReason?: string | null;
 }
 
 export interface BCSyncPreviewResult {
@@ -59,6 +61,7 @@ export interface BCSyncApplyResult {
     itemUnitsOfMeasure: { applied: boolean; reason?: string; url?: string };
   };
   error?: string;
+  warning?: string;
 }
 
 async function readResponsePayload(res: Response): Promise<{ data: any; rawText: string }> {