feat(server): 票据增强闭环（F9/F10/F11/F12/F13/F28）

- /invoice-pool 新增 unbind、PATCH 修正、manual archive、OCR retry、判重例外 override（含 VALID_004/006/007）

- signed-url 签发/下载写入审计日志（脱敏 extra）

- 新增未绑定票据自动归档作业 + 一次性执行脚本

- 回归脚本增强：workflow-actions/dedup/audit/ocr 覆盖上述场景；v3 CSV 状态推进至 DONE

server/src/jobs/invoiceArchiveJob.js

@@ -0,0 +1,110 @@
+const cron = require("node-cron");
+
+async function claimAndArchiveUnusedInvoices(tx, batchSize, unusedDays) {
+  return tx.$queryRaw`
+    WITH picked AS (
+      SELECT id
+      FROM "invoice_pool"
+      WHERE linked_reimbursement_id IS NULL
+        AND status IN ('available', 'ocr_failed')
+        AND created_at < NOW() - make_interval(days => ${unusedDays})
+      ORDER BY created_at ASC
+      LIMIT ${batchSize}
+      FOR UPDATE SKIP LOCKED
+    )
+    UPDATE "invoice_pool" AS i
+    SET status = 'archived',
+        archived_reason = 'unused_timeout',
+        archived_at = NOW(),
+        linked_item_id = NULL,
+        ocr_locked_at = NULL,
+        ocr_lock_owner = NULL,
+        updated_by = NULL
+    FROM picked
+    WHERE i.id = picked.id
+      AND i.linked_reimbursement_id IS NULL
+      AND i.status IN ('available', 'ocr_failed')
+    RETURNING i.id, i.owner_employee_id, i.status, i.archived_at
+  `;
+}
+
+async function archiveUnusedInvoices(prisma, logger, options = {}) {
+  const batchSize = Math.max(1, Number(options.batchSize ?? 200));
+  const unusedDays = Math.max(1, Number(options.unusedDays ?? 90));
+
+  let total = 0;
+  let round = 0;
+
+  while (true) {
+    round += 1;
+
+    const archivedRows = await prisma.$transaction(async (tx) => {
+      return claimAndArchiveUnusedInvoices(tx, batchSize, unusedDays);
+    });
+
+    if (!archivedRows.length) {
+      break;
+    }
+
+    total += archivedRows.length;
+    logger.info(
+      {
+        round,
+        claimed: archivedRows.length,
+        updated: archivedRows.length,
+        archived: archivedRows.length,
+        unusedDays,
+      },
+      "Unused invoices archived batch processed",
+    );
+  }
+
+  if (total > 0) {
+    logger.info({ archived: total, unusedDays }, "Unused invoices auto-archived");
+  }
+
+  return total;
+}
+
+function startInvoiceArchiveJob(fastify) {
+  let running = false;
+
+  const task = cron.schedule(fastify.config.invoiceArchiveCron, async () => {
+    if (running) {
+      return;
+    }
+
+    running = true;
+    try {
+      await archiveUnusedInvoices(fastify.prisma, fastify.log, {
+        batchSize: fastify.config.invoiceArchiveBatchSize,
+        unusedDays: fastify.config.invoiceArchiveUnusedDays,
+      });
+    } catch (error) {
+      fastify.log.error({ err: error }, "Invoice archive job failed");
+    } finally {
+      running = false;
+    }
+  });
+
+  fastify.addHook("onClose", async () => {
+    task.stop();
+    task.destroy();
+  });
+
+  fastify.log.info(
+    {
+      cron: fastify.config.invoiceArchiveCron,
+      unusedDays: fastify.config.invoiceArchiveUnusedDays,
+    },
+    "Invoice archive job scheduled",
+  );
+
+  return task;
+}
+
+module.exports = {
+  archiveUnusedInvoices,
+  startInvoiceArchiveJob,
+};
+