diff --git a/backend/pyproject.toml b/backend/pyproject.toml
index a1d4e4f..02cd526 100644
--- a/backend/pyproject.toml
+++ b/backend/pyproject.toml
@@ -10,6 +10,7 @@ dependencies = [
   "pydantic>=2.7.0",
   "sqlalchemy>=2.0.30",
   "psycopg[binary]>=3.2.1",
+  "psycopg-pool>=3.2.1",
   "alembic>=1.13.1",
   "redis>=5.0.4",
   "httpx>=0.27.0",
diff --git a/backend/requirements.txt b/backend/requirements.txt
index 900f72b..04e346a 100644
--- a/backend/requirements.txt
+++ b/backend/requirements.txt
@@ -4,6 +4,7 @@ python-multipart>=0.0.9
 pydantic>=2.7.0
 sqlalchemy>=2.0.30
 psycopg[binary]>=3.2.1
+psycopg-pool>=3.2.1
 alembic>=1.13.1
 redis>=5.0.4
 httpx>=0.27.0
diff --git a/docker/app/Dockerfile.backend b/docker/app/Dockerfile.backend
index 1f03dca..c5a7195 100644
--- a/docker/app/Dockerfile.backend
+++ b/docker/app/Dockerfile.backend
@@ -11,7 +11,7 @@ RUN pip install --upgrade pip -i https://pypi.tuna.tsinghua.edu.cn/simple \
     && pip install -r /tmp/requirements.txt -i https://pypi.tuna.tsinghua.edu.cn/simple \
     && rm -f /tmp/requirements.txt
 
-RUN python -c "import fastapi, uvicorn, psycopg, sqlalchemy, redis, jwt, passlib, httpx, alembic; print('backend dependency check ok')"
+RUN python -c "import fastapi, uvicorn, psycopg, psycopg_pool, sqlalchemy, redis, jwt, passlib, httpx, alembic; print('backend dependency check ok')"
 
 RUN mkdir -p /opt/yg-ft/logs/backend /data/yg-ft \
     && chmod -R 0775 /opt/yg-ft /data/yg-ft
diff --git a/frontend/src/views/approvals/ApprovalInstanceView.vue b/frontend/src/views/approvals/ApprovalInstanceView.vue
index db29b4f..4664758 100644
--- a/frontend/src/views/approvals/ApprovalInstanceView.vue
+++ b/frontend/src/views/approvals/ApprovalInstanceView.vue
@@ -3,7 +3,8 @@ import { onMounted, reactive, ref } from 'vue'
 import { ElMessage } from 'element-plus'
 import DataTablePage from '@/components/DataTablePage.vue'
 import { getApprovalInstances, decideApproval, type ApprovalInstance } from '@/api/modules/approval'
-import { getUsers, type SystemUser } from '@/api/modules/system'
+import { getUsers } from '@/api/modules/system'
+import type { SystemUser } from '@/types'
 
 const loading = ref(false)
 const instances = ref<ApprovalInstance[]>([])
@@ -48,6 +49,10 @@ function openDecide(inst: ApprovalInstance) {
   showDecide.value = true
 }
 
+function asApprovalInstance(row: unknown): ApprovalInstance {
+  return row as ApprovalInstance
+}
+
 async function submitDecision() {
   if (!current.value) return
   if (!decision.value.approver_id) {
@@ -72,7 +77,7 @@ onMounted(() => {
 
 <template>
   <div class="page">
-    <DataTablePage title="审批实例" :data="instances" :loading="loading" searchable search-fields="resource_type,resource_id">
+    <DataTablePage title="审批实例" :data="instances" :loading="loading" searchable :search-fields="['resource_type', 'resource_id']">
       <template #toolbar-extra>
         <el-select v-model="statusFilter" placeholder="状态" clearable style="width: 140px" @change="load">
           <el-option v-for="s in statusOptions" :key="s.value" :label="s.label" :value="s.value" />
@@ -82,14 +87,14 @@ onMounted(() => {
         <el-table-column prop="resource_type" label="资源类型" min-width="120" />
         <el-table-column prop="resource_id" label="资源 ID" min-width="160" show-overflow-tooltip />
         <el-table-column prop="applicant_id" label="申请人" min-width="120">
-          <template #default="{ row }">{{ userName(row.applicant_id) }}</template>
+          <template #default="{ row }">{{ userName(asApprovalInstance(row).applicant_id) }}</template>
         </el-table-column>
         <el-table-column prop="status" label="状态" min-width="100" />
         <el-table-column prop="current_step" label="当前步骤" min-width="100" />
         <el-table-column prop="create_time" label="创建时间" min-width="180" />
       </template>
       <template #actions="{ row }">
-        <el-button v-if="row.status === 'pending'" link type="primary" @click="openDecide(row)">审批</el-button>
+        <el-button v-if="asApprovalInstance(row).status === 'pending'" link type="primary" @click="openDecide(asApprovalInstance(row))">审批</el-button>
       </template>
     </DataTablePage>
     <el-dialog v-model="showDecide" title="审批决策" width="480px">
diff --git a/frontend/src/views/projects/ProjectDetailView.vue b/frontend/src/views/projects/ProjectDetailView.vue
index 7ab05d9..eda4241 100644
--- a/frontend/src/views/projects/ProjectDetailView.vue
+++ b/frontend/src/views/projects/ProjectDetailView.vue
@@ -5,7 +5,8 @@ import { ElMessage } from 'element-plus'
 import DataTablePage from '@/components/DataTablePage.vue'
 import AclDialog from '@/components/AclDialog.vue'
 import { getProject, getProjectMembers, addProjectMember, removeProjectMember, type Project, type ProjectMember } from '@/api/modules/project'
-import { getUsers, type SystemUser } from '@/api/modules/system'
+import { getUsers } from '@/api/modules/system'
+import type { SystemUser } from '@/types'
 
 const route = useRoute()
 const router = useRouter()
@@ -56,6 +57,10 @@ async function removeMember(userId: string) {
   load()
 }
 
+function asProjectMember(row: unknown): ProjectMember {
+  return row as ProjectMember
+}
+
 onMounted(() => {
   loadUsers()
   load()
@@ -94,7 +99,7 @@ onMounted(() => {
           <el-table-column prop="create_time" label="加入时间" min-width="180" />
         </template>
         <template #actions="{ row }">
-          <el-button link type="danger" @click="removeMember(row.user_id)">移除</el-button>
+          <el-button link type="danger" @click="removeMember(asProjectMember(row).user_id)">移除</el-button>
         </template>
       </DataTablePage>
     </el-card>
diff --git a/frontend/src/views/projects/ProjectListView.vue b/frontend/src/views/projects/ProjectListView.vue
index 5f9447b..9deff91 100644
--- a/frontend/src/views/projects/ProjectListView.vue
+++ b/frontend/src/views/projects/ProjectListView.vue
@@ -41,6 +41,10 @@ function openDetail(id: string) {
   router.push(`/projects/${id}`)
 }
 
+function asProject(row: unknown): Project {
+  return row as Project
+}
+
 async function submitCreate() {
   if (!form.value.name || !form.value.code) {
     ElMessage.warning('请填写项目名与编码')
@@ -61,7 +65,7 @@ onMounted(() => {
 
 <template>
   <div class="page">
-    <DataTablePage title="项目空间" :data="projects" :loading="loading" searchable search-fields="name,code">
+    <DataTablePage title="项目空间" :data="projects" :loading="loading" searchable :search-fields="['name', 'code']">
       <template #toolbar-extra>
         <el-select v-model="tenantId" placeholder="租户" style="width: 160px" @change="load">
           <el-option v-for="t in tenantOptions" :key="t.value" :label="t.label" :value="t.value" />
@@ -76,7 +80,7 @@ onMounted(() => {
         <el-table-column prop="create_time" label="创建时间" min-width="180" />
       </template>
       <template #actions="{ row }">
-        <el-button link type="primary" @click="openDetail(row.id)">详情</el-button>
+        <el-button link type="primary" @click="openDetail(asProject(row).id)">详情</el-button>
       </template>
     </DataTablePage>
     <el-dialog v-model="showCreate" title="新建项目" width="520px">
diff --git a/frontend/src/views/system/UserSettingsView.vue b/frontend/src/views/system/UserSettingsView.vue
index 2ddb063..80750cf 100644
--- a/frontend/src/views/system/UserSettingsView.vue
+++ b/frontend/src/views/system/UserSettingsView.vue
@@ -54,6 +54,18 @@ function isSelf(row: SystemUser) {
   return row.username === currentUsername.value
 }
 
+function asSystemUser(row: unknown): SystemUser {
+  return row as SystemUser
+}
+
+function userPermissions(row: unknown): PermissionCode[] {
+  return (asSystemUser(row).permissions || []) as PermissionCode[]
+}
+
+function permissionLabel(code: PermissionCode): string {
+  return PERMISSION_LABELS[code] || code
+}
+
 // ---------- 启停 ----------
 async function toggleStatus(row: SystemUser, next: boolean) {
   const nextStatus: UserStatus = next ? 'active' : 'disabled'
@@ -162,31 +174,31 @@ async function removeUser(row: SystemUser) {
       <el-table-column prop="role" label="角色" width="120" />
       <el-table-column label="状态" width="130">
         <template #default="{ row }">
-          <el-tag :type="statusTagType(row.status)" size="small">{{ statusLabel(row.status) }}</el-tag>
+          <el-tag :type="statusTagType(asSystemUser(row).status)" size="small">{{ statusLabel(asSystemUser(row).status) }}</el-tag>
         </template>
       </el-table-column>
       <el-table-column label="页面权限" min-width="160">
         <template #default="{ row }">
           <el-tag
-            v-for="p in (row.permissions || []).slice(0, 3)"
+            v-for="p in userPermissions(row).slice(0, 3)"
             :key="p"
             size="small"
             type="info"
             class="perm-tag"
-          >{{ PERMISSION_LABELS[p] || p }}</el-tag>
-          <span v-if="(row.permissions || []).length > 3" class="perm-more">
-            +{{ (row.permissions || []).length - 3 }}
+          >{{ permissionLabel(p) }}</el-tag>
+          <span v-if="userPermissions(row).length > 3" class="perm-more">
+            +{{ userPermissions(row).length - 3 }}
           </span>
-          <span v-if="!(row.permissions || []).length" class="perm-more">无</span>
+          <span v-if="!userPermissions(row).length" class="perm-more">无</span>
         </template>
       </el-table-column>
       <el-table-column prop="create_time" label="创建时间" min-width="180" />
       <el-table-column label="操作" width="260" fixed="right">
         <template #default="{ row }">
           <el-switch
-            :model-value="row.status === 'active'"
-            :disabled="row.protected || isSelf(row)"
-            @change="(v: any) => toggleStatus(row, v)"
+            :model-value="asSystemUser(row).status === 'active'"
+            :disabled="asSystemUser(row).protected || isSelf(asSystemUser(row))"
+            @change="(v: any) => toggleStatus(asSystemUser(row), v)"
             inline-prompt
             active-text="启用"
             inactive-text="停用"
@@ -194,19 +206,19 @@ async function removeUser(row: SystemUser) {
           <el-button
             link
             type="primary"
-            :disabled="row.protected"
-            @click="openResetPwd(row)"
+            :disabled="asSystemUser(row).protected"
+            @click="openResetPwd(asSystemUser(row))"
           >重置密码</el-button>
           <el-button
             link
             type="primary"
-            @click="openPerms(row)"
+            @click="openPerms(asSystemUser(row))"
           >页面权限</el-button>
           <el-button
             link
             type="danger"
-            :disabled="row.protected || isSelf(row)"
-            @click="removeUser(row)"
+            :disabled="asSystemUser(row).protected || isSelf(asSystemUser(row))"
+            @click="removeUser(asSystemUser(row))"
           >删除</el-button>
         </template>
       </el-table-column>
diff --git a/frontend/src/views/tenants/TenantListView.vue b/frontend/src/views/tenants/TenantListView.vue
index 087d0b3..0203df3 100644
--- a/frontend/src/views/tenants/TenantListView.vue
+++ b/frontend/src/views/tenants/TenantListView.vue
@@ -25,6 +25,15 @@ function openDetail(id: string) {
   router.push(`/tenants/${id}`)
 }
 
+function asTenant(row: unknown): Tenant {
+  return row as Tenant
+}
+
+function quotaText(row: unknown): string {
+  const quota = asTenant(row).quota || {}
+  return Object.keys(quota).length ? JSON.stringify(quota) : '—'
+}
+
 async function submitCreate() {
   if (!form.value.name) {
     ElMessage.warning('请填写租户名称')
@@ -75,15 +84,15 @@ onMounted(load)
         <el-table-column prop="code" label="编码" min-width="100" />
         <el-table-column label="配额" min-width="160">
           <template #default="{ row }">
-            {{ Object.keys(row.quota || {}).length ? JSON.stringify(row.quota) : '—' }}
+            {{ quotaText(row) }}
           </template>
         </el-table-column>
         <el-table-column prop="status" label="状态" min-width="100" />
         <el-table-column prop="create_time" label="创建时间" min-width="180" />
       </template>
       <template #actions="{ row }">
-        <el-button link type="primary" @click="openDetail(row.id)">详情</el-button>
-        <el-button link type="primary" @click="setQuota(row)">配额</el-button>
+        <el-button link type="primary" @click="openDetail(asTenant(row).id)">详情</el-button>
+        <el-button link type="primary" @click="setQuota(asTenant(row))">配额</el-button>
       </template>
     </DataTablePage>
     <el-dialog v-model="showCreate" title="新建租户" width="520px">