feat(borrow): 前端转交/流转明细 UI 与借用人选人适配

转交 UI（借还记录页）
----
· 操作列新增【转交】，v-permission="'borrow_transfer'" + 按钮 loading 防抖
· 弹窗明示「仅支持整单全部转交」与「转交后须由接收人本人归还」，并在确认框
  复述接收人与转交数量
· 列表是 borrow_no 主子表结构，trans_borrow.id 在**明细行**上，而一张单的明细
  可各有不同持有人（转交是逐条明细进行的），故弹窗先让用户选定明细；单条明细
  时自动选中（实测 54/60 的单号只有 1 条，等于零额外点击）。
  该「单号按钮 → 弹窗选明细」范式沿用本页既有的「申请报废」。

流转明细时间线
----
· 操作列新增【流转记录】，无特殊权限要求（页面本身已由 op_records 把守）
· Drawer + el-timeline 倒序展示 借出 → 转交(可多次) → 归还 → 报废，
  每节点显示时间、动作、当事人（借用人 / 转出→接收 / 实际归还人）与经手库管，
  转交备注一并展示
· 主列表新增「当前持有人」列：转交后可能与「借用人」不是同一人；一张单的明细
  持有人可能不同，去重后逐个展示，已全部回库显示「已回库」

身份锚点适配
----
· 借出页：借用人由「自由输入姓名」改为「用户下拉」，提交 borrower_id
  （姓名无法唯一锚定一个人，重名即责任链断裂）
· 归还页：新增「实际归还人」下拉，默认取首件物品的当前持有人，提交 returner_id；
  主表新增「当前持有人」列提示库管该由谁来还
· 错误提示不再本地重复弹出 —— request 拦截器已按后端 msg 全局 toast，
  再弹一次会双份

验证：vite build 通过；接口契约经后端回归用例校验。

inventory-web/src/views/transaction/records.vue

@@ -137,6 +137,23 @@
 
       <el-table-column v-if="hasColumnPermission('borrow_no')" prop="borrow_no" label="单号" width="180" show-overflow-tooltip />
       <el-table-column v-if="hasColumnPermission('borrower_name')" prop="borrower_name" label="借用人" width="100" />
+      <!-- ★ 当前持有人：转交后可能与「借用人」不是同一人。
+           一张单的明细可能持有人各不相同，故去重后逐个展示。 -->
+      <el-table-column label="当前持有人" width="120">
+        <template #default="{row}">
+          <template v-if="currentHolders(row).length">
+            <el-tag
+                v-for="h in currentHolders(row)"
+                :key="h"
+                type="warning"
+                size="small"
+                style="margin: 1px 2px"
+            >{{ h }}</el-tag>
+          </template>
+          <span v-else-if="row.status === 'returned'" style="color: #67C23A; font-size: 12px">已回库</span>
+          <span v-else style="color: #c0c4cc">—</span>
+        </template>
+      </el-table-column>
       <el-table-column v-if="hasColumnPermission('borrow_time')" prop="borrow_time" label="借出时间" width="160" sortable />
       <el-table-column label="借出物品" width="90" align="center">
         <template #default="{row}">
@@ -192,14 +209,28 @@
         </template>
       </el-table-column>
 
-      <!-- ★ 报废操作列：仅未归还记录 + 库管/主管可见 -->
-      <el-table-column v-if="canScrap" label="操作" width="90" align="center" fixed="right">
+      <!-- ★ 操作列
+             · 申请报废 / 转交 —— 仅未归还记录，且分别受各自权限约束
+             · 流转记录 —— 无特殊权限要求，凡能看到本列表者皆可查看 -->
+      <el-table-column label="操作" width="210" align="center" fixed="right">
         <template #default="{row}">
           <el-button
-              v-if="row.status === 'borrowed' || row.status === 'partial_returned'"
+              v-if="canScrap && isUnreturned(row)"
               type="danger" link size="small"
               @click="openScrapDialog(row)"
           >申请报废</el-button>
+
+          <el-button
+              v-if="isUnreturned(row)"
+              v-permission="'borrow_transfer'"
+              type="primary" link size="small"
+              @click="openTransferDialog(row)"
+          >转交</el-button>
+
+          <el-button
+              type="info" link size="small"
+              @click="openHistoryDrawer(row)"
+          >流转记录</el-button>
         </template>
       </el-table-column>
     </el-table>
@@ -256,6 +287,115 @@
         <el-button type="danger" :loading="scrapSubmitting" @click="confirmScrap">提交报废申请</el-button>
       </template>
     </el-dialog>
+
+    <!-- ★ 借库转交弹窗（一期：仅支持整单全部转交） -->
+    <el-dialog v-model="transferDialogVisible" title="借库转交" width="640px" destroy-on-close>
+      <el-alert
+          title="仅支持整单全部转交"
+          description="一张借出单同时只能有一个持有人。部分转交会让「当前持有人」无法确定，故一期不支持；如需拆分持有，请先办理部分归还，再对剩余量转交。"
+          type="warning"
+          :closable="false"
+          show-icon
+          style="margin-bottom: 14px"
+      />
+      <div style="margin-bottom: 10px;">
+        <div style="font-weight: 600; margin-bottom: 6px;">单号：{{ transferBorrowNo }}</div>
+        <div style="font-size: 13px; color: #909399;">请选择要转交的明细（转交后该明细的持有人整体变更为接收人）：</div>
+      </div>
+      <el-table
+          :data="transferCandidates"
+          border
+          size="small"
+          max-height="260"
+          highlight-current-row
+          @row-click="(row: any) => transferTargetId = row.id"
+      >
+        <el-table-column width="46" align="center">
+          <template #default="{row}">
+            <el-radio v-model="transferTargetId" :value="row.id" :label="row.id">&nbsp;</el-radio>
+          </template>
+        </el-table-column>
+        <el-table-column prop="material_name" label="物料名称" min-width="130" show-overflow-tooltip />
+        <el-table-column prop="sku" label="SKU" width="110" show-overflow-tooltip />
+        <el-table-column label="当前持有人" width="100" align="center">
+          <template #default="{row}">
+            <el-tag type="warning" size="small">{{ row.current_holder_name || '—' }}</el-tag>
+          </template>
+        </el-table-column>
+        <el-table-column label="待还数量" width="90" align="center">
+          <template #default="{row}">
+            <span style="color:#F56C6C; font-weight:bold">{{ row.pending_quantity }}</span>
+          </template>
+        </el-table-column>
+      </el-table>
+
+      <el-form label-width="80px" style="margin-top: 14px;">
+        <el-form-item label="接收人" required>
+          <el-select v-model="transferToUserId" placeholder="请选择接收人" style="width: 100%" filterable>
+            <el-option v-for="u in transferUsers" :key="u.id" :label="u.name" :value="u.id" />
+          </el-select>
+        </el-form-item>
+        <el-form-item label="转交备注">
+          <el-input
+              v-model="transferRemark"
+              type="textarea"
+              :rows="2"
+              placeholder="如：项目交接 / 人员离岗，可留空"
+          />
+        </el-form-item>
+      </el-form>
+      <template #footer>
+        <el-button @click="transferDialogVisible = false">取消</el-button>
+        <el-button type="primary" :loading="transferSubmitting" @click="confirmTransfer">确认转交</el-button>
+      </template>
+    </el-dialog>
+
+    <!-- ★ 流转明细时间线：借出 → 转交(可多次) → 归还 → 报废，倒序展示 -->
+    <el-drawer v-model="historyDrawerVisible" title="流转明细" size="580px" destroy-on-close>
+      <div v-loading="historyLoading">
+        <div style="font-weight: 600; margin-bottom: 4px;">单号：{{ historyBorrowNo }}</div>
+        <div style="font-size: 12px; color: #909399; margin-bottom: 16px;">
+          按时间倒序，最新动作在最上方
+        </div>
+        <el-empty v-if="!historyEvents.length" description="暂无流转记录" :image-size="70" />
+        <el-timeline v-else>
+          <el-timeline-item
+              v-for="(e, i) in historyEvents"
+              :key="i"
+              :timestamp="e.time"
+              placement="top"
+              :type="eventMeta(e.type).type"
+              :hollow="e.type === 'borrow'"
+          >
+            <div style="display:flex; align-items:center; gap:8px; margin-bottom:4px;">
+              <el-tag :type="eventMeta(e.type).type" size="small">{{ eventMeta(e.type).label }}</el-tag>
+              <span style="font-size: 13px; color:#606266;">{{ e.material_name || e.sku }}</span>
+              <span style="font-size: 13px; color:#909399;">× {{ e.quantity }}</span>
+            </div>
+            <div style="font-size: 13px; color:#303133;">
+              <template v-if="e.type === 'borrow'">
+                借用人：<b>{{ e.actor_name || '—' }}</b>
+                <span v-if="e.operator_name" style="color:#909399;"> · 发货库管：{{ e.operator_name }}</span>
+              </template>
+              <template v-else-if="e.type === 'transfer'">
+                <b>{{ e.from_name || '—' }}</b> → <b>{{ e.actor_name || '—' }}</b>
+                <span v-if="e.operator_name" style="color:#909399;"> · 经手库管：{{ e.operator_name }}</span>
+              </template>
+              <template v-else-if="e.type === 'return'">
+                归还人：<b>{{ e.actor_name || '—' }}</b>
+                <span v-if="e.operator_name" style="color:#909399;"> · 经手库管：{{ e.operator_name }}</span>
+              </template>
+              <template v-else>
+                报废 · 经手库管：<b>{{ e.operator_name || '—' }}</b>
+              </template>
+            </div>
+            <div v-if="e.remark" style="font-size: 12px; color:#909399; margin-top:2px;">
+              备注：{{ e.remark }}
+            </div>
+          </el-timeline-item>
+        </el-timeline>
+      </div>
+    </el-drawer>
   </div>
 </template>
 
@@ -268,7 +408,12 @@ import 'dayjs/locale/zh-cn'
 dayjs.locale('zh-cn')
 import { useUserStore } from '@/stores/user'
 import { getApproversList } from '@/api/auth'
-import { submitBorrowScrapRequest } from '@/api/transaction'
+import {
+  submitBorrowScrapRequest,
+  transferBorrow,
+  getBorrowUsers,
+  getBorrowSlipHistory,
+} from '@/api/transaction'
 
 const userStore = useUserStore()
 
@@ -450,6 +595,131 @@ const confirmScrap = async () => {
   }
 }
 
+// ==========================================================================
+// ★ 借库转交（一期：仅支持整单全部转交）
+// ==========================================================================
+// 未归还判定：主表状态下 borrowed / partial_returned 都还有实物未回库
+const isUnreturned = (row: any) =>
+  row.status === 'borrowed' || row.status === 'partial_returned'
+
+// 当前持有人：整单下各明细可能持有人不同（转交是逐条明细进行的），去重后展示
+const currentHolders = (row: any): string[] => {
+  const names = (row.children || [])
+    .map((c: any) => c.current_holder_name)
+    .filter((n: any) => !!n)
+  return Array.from(new Set(names)) as string[]
+}
+
+const transferDialogVisible = ref(false)
+const transferSubmitting = ref(false)
+const transferBorrowNo = ref('')
+const transferCandidates = ref<any[]>([])
+const transferTargetId = ref<number | null>(null)
+const transferToUserId = ref<number | null>(null)
+const transferRemark = ref('')
+const transferUsers = ref<Array<{ id: number; name: string }>>([])
+
+const loadTransferUsers = async () => {
+  if (transferUsers.value.length) return   // 名单会话内复用，避免每次开弹窗都请求
+  try {
+    const res: any = await getBorrowUsers()
+    transferUsers.value = res?.data || []
+  } catch {
+    transferUsers.value = []
+  }
+}
+
+const openTransferDialog = (row: any) => {
+  // 仅未还清的明细可转交（与后端的状态准入一致）
+  const candidates = (row.children || []).filter((c: any) => (c.pending_quantity || 0) > 0)
+  if (!candidates.length) {
+    ElMessage.warning('该单号下没有未归还的明细，无法转交')
+    return
+  }
+  transferBorrowNo.value = row.borrow_no
+  transferCandidates.value = candidates
+  // 实测 54/60 的单号只有 1 条明细 —— 单条时直接选中，省掉一次点击
+  transferTargetId.value = candidates.length === 1 ? candidates[0].id : null
+  transferToUserId.value = null
+  transferRemark.value = ''
+  transferDialogVisible.value = true
+  loadTransferUsers()
+}
+
+const confirmTransfer = async () => {
+  if (!transferTargetId.value) return ElMessage.warning('请选择要转交的明细')
+  if (!transferToUserId.value) return ElMessage.warning('请选择接收人')
+
+  const target = transferCandidates.value.find((c: any) => c.id === transferTargetId.value)
+  const receiver = transferUsers.value.find(u => u.id === transferToUserId.value)
+
+  // 提前拦截「转给自己」，省一次无效往返（后端也会拒）
+  if (target && receiver && target.current_holder_id === receiver.id) {
+    return ElMessage.warning(`接收人与当前持有人同为【${receiver.name}】，无需转交`)
+  }
+
+  const qty = target?.pending_quantity ?? 0
+  try {
+    await ElMessageBox.confirm(
+      `将【${target?.material_name || target?.sku || ''}】的持有权整单转交给【${receiver?.name || ''}】？\n\n`
+      + `转交数量：${qty}（整单全量，不支持部分转交）\n`
+      + `转交后，该物品须由接收人本人办理归还。`,
+      '转交确认',
+      { confirmButtonText: '确认转交', cancelButtonText: '取消', type: 'warning' }
+    )
+  } catch {
+    return // 用户取消
+  }
+
+  transferSubmitting.value = true   // ★ 按钮 loading 防抖，避免重复提交
+  try {
+    const res: any = await transferBorrow(transferTargetId.value, {
+      transfer_qty: qty,             // 一期必须等于待还量，后端会二次校验
+      to_user_id: transferToUserId.value,
+      to_user_name: receiver?.name,
+      remark: transferRemark.value,
+    })
+    ElMessage.success(res?.msg || '转交成功')
+    transferDialogVisible.value = false
+    fetchData()                      // 刷新列表：持有人/操作列状态已变化
+  } catch {
+    // ★ 不重复弹错：request 拦截器已按后端 msg 全局 toast，此处再弹会双份
+  } finally {
+    transferSubmitting.value = false
+  }
+}
+
+// ==========================================================================
+// ★ 流转明细时间线（借出 → 转交(可多次) → 归还 → 报废）
+// ==========================================================================
+const historyDrawerVisible = ref(false)
+const historyLoading = ref(false)
+const historyBorrowNo = ref('')
+const historyEvents = ref<any[]>([])
+
+const EVENT_META: Record<string, { label: string; type: any }> = {
+  borrow:   { label: '借出', type: 'primary' },
+  transfer: { label: '转交', type: 'warning' },
+  return:   { label: '归还', type: 'success' },
+  scrap:    { label: '报废', type: 'danger' },
+}
+const eventMeta = (t: string) => EVENT_META[t] || { label: t, type: 'info' }
+
+const openHistoryDrawer = async (row: any) => {
+  historyBorrowNo.value = row.borrow_no
+  historyEvents.value = []
+  historyDrawerVisible.value = true
+  historyLoading.value = true
+  try {
+    const res: any = await getBorrowSlipHistory(row.borrow_no)
+    historyEvents.value = res?.data?.events || []
+  } catch {
+    // 同上：错误提示由 request 拦截器统一处理
+  } finally {
+    historyLoading.value = false
+  }
+}
+
 const fetchData = async () => {
   loading.value = true
   try {