feat: expose idempotent N0D-backed batch ER submission

app/api/0pt/er/batch/route.ts

@@ -0,0 +1,44 @@
+import { NextRequest, NextResponse } from "next/server";
+
+import { assertTenantMatchesVerified } from "@/src/http/tenant-guard";
+import { siaxErrorResponse } from "@/src/http/siax-error-response";
+import { SiaxError } from "@/src/platform/errors";
+import { getBatchEntityResolutionService } from "@/src/services/entity-resolution";
+
+function required(body: Record<string, unknown>, field: string): string {
+  const value = body[field];
+  if (typeof value !== "string" || !value.trim()) {
+    throw new SiaxError("INVALID_REQUEST", "0pt.er", `${field} is required`);
+  }
+  return value.trim();
+}
+
+export async function POST(request: NextRequest) {
+  try {
+    const raw = await request.json();
+    if (!raw || typeof raw !== "object" || Array.isArray(raw)) {
+      throw new SiaxError("INVALID_REQUEST", "0pt.er", "JSON object body is required");
+    }
+    const body = raw as Record<string, unknown>;
+    const tenantId = required(body, "tenant_id");
+    const guard = assertTenantMatchesVerified(request, tenantId);
+    if (guard) return guard;
+
+    const idempotencyKey = request.headers.get("idempotency-key")?.trim()
+      || (typeof body.idempotency_key === "string" ? body.idempotency_key.trim() : "")
+      || undefined;
+    const job = await getBatchEntityResolutionService().submitBatchResolution({
+      tenant_id: tenantId,
+      project_id: required(body, "project_id"),
+      records_artifact_ref: required(body, "records_artifact_ref"),
+      actor_id: request.headers.get("x-0pt-verified-sub") ?? "local-dev",
+      ...(typeof body.correlation_id === "string" && body.correlation_id.trim()
+        ? { correlation_id: body.correlation_id.trim() }
+        : {}),
+      ...(idempotencyKey ? { idempotency_key: idempotencyKey } : {}),
+    });
+    return NextResponse.json(job, { status: 202 });
+  } catch (error: unknown) {
+    return siaxErrorResponse(error);
+  }
+}