fix(sync): link domains to subscriptions and add backfill endpoint

app/api/plesk/instances/[id]/backfill-domain-links/route.ts

@@ -0,0 +1,51 @@
+import { NextResponse } from "next/server";
+
+import { assertAgencyAdmin, getRouteAgencyContextOrThrow } from "@/lib/agency";
+import { assertRateLimit } from "@/lib/api/rate-limit";
+import { assertSameOrigin } from "@/lib/api/security";
+import { backfillDomainSubscriptionLinks } from "@/lib/plesk/sync";
+import { createSupabaseRouteClient } from "@/lib/supabase/route";
+
+export async function POST(
+  req: Request,
+  { params }: { params: { id: string } },
+) {
+  try {
+    assertSameOrigin(req);
+
+    const context = await getRouteAgencyContextOrThrow();
+    assertAgencyAdmin(context);
+    assertRateLimit(`plesk-backfill-links:${context.userId}`, 5, 60_000);
+
+    const supabase = createSupabaseRouteClient() as any;
+
+    const { data: instance, error: instanceError } = await supabase
+      .from("plesk_instances")
+      .select("id")
+      .eq("id", params.id)
+      .eq("agency_id", context.agencyId)
+      .single();
+
+    if (instanceError || !instance) {
+      throw new Error("Plesk instance not found");
+    }
+
+    const result = await backfillDomainSubscriptionLinks(supabase, {
+      agencyId: context.agencyId,
+      instanceId: params.id,
+      actorUserId: context.userId,
+    });
+
+    return NextResponse.json({ ok: true, ...result });
+  } catch (error) {
+    return NextResponse.json(
+      {
+        error:
+          error instanceof Error
+            ? error.message
+            : "Backfill domain links failed",
+      },
+      { status: 400 },
+    );
+  }
+}