feat: 多用户管理系统，管理员可分配用户

- 新增 users 数据库表，存储用户名、密码哈希、角色
- 启动时自动从 .env 创建初始管理员账号
- 登录改为数据库校验，不再硬编码比对
- 新增 /api/users 管理接口（仅管理员）
- ConfigView 新增用户管理页（创建、改密码、切换角色、删除）

frontend/src/views/ConfigView.vue

@@ -9,6 +9,7 @@
       <div class="sidebar">
         <h3>配置管理</h3>
         <ul class="sidebar-menu">
+          <li :class="{ active: tab === 'users' }" @click="tab = 'users'">用户管理</li>
           <li :class="{ active: tab === 'servers' }" @click="tab = 'servers'">服务器环境</li>
           <li :class="{ active: tab === 'apps' }" @click="tab = 'apps'">Apps 配置</li>
           <li :class="{ active: tab === 'schemes' }" @click="tab = 'schemes'">Schemes 配置</li>
@@ -19,6 +20,42 @@
         </ul>
       </div>
       <div class="main-content">
+        <!-- 用户管理 -->
+        <div v-if="tab === 'users'">
+          <h2>用户管理</h2>
+          <p style="color: #666; margin-bottom: 16px; font-size: 14px;">管理员可以创建和管理普通用户账号</p>
+          <button class="btn btn-primary" style="width: auto; margin-bottom: 16px;" @click="openUserModal()">+ 新增用户</button>
+          <table class="config-table">
+            <thead>
+              <tr>
+                <th>用户名</th>
+                <th>角色</th>
+                <th>创建时间</th>
+                <th>操作</th>
+              </tr>
+            </thead>
+            <tbody>
+              <tr v-for="u in users" :key="u.id">
+                <td><strong>{{ u.username }}</strong></td>
+                <td>
+                  <span :class="['build-type-badge', u.is_admin ? 'badge-appstore' : 'badge-adhoc']">
+                    {{ u.is_admin ? '管理员' : '普通用户' }}
+                  </span>
+                </td>
+                <td>{{ u.created_at || '-' }}</td>
+                <td class="action-btns">
+                  <button class="action-btn" @click="openPasswordModal(u)">改密码</button>
+                  <button class="action-btn" @click="toggleUserRole(u)">{{ u.is_admin ? '取消管理员' : '设为管理员' }}</button>
+                  <button class="action-btn delete" @click="deleteUser(u)">删除</button>
+                </td>
+              </tr>
+              <tr v-if="!users.length">
+                <td colspan="4" style="text-align: center; color: #999;">暂无用户</td>
+              </tr>
+            </tbody>
+          </table>
+        </div>
+
         <!-- 服务器环境配置 -->
         <div v-if="tab === 'servers'">
           <h2>服务器环境配置</h2>
@@ -275,6 +312,52 @@
       </div>
     </div>
 
+    <!-- 新增用户弹窗 -->
+    <div v-if="showUserModal" class="modal-overlay" @click.self="showUserModal = false">
+      <div class="modal-content">
+        <div class="modal-header">
+          <h3>新增用户</h3>
+          <button class="modal-close" @click="showUserModal = false">&times;</button>
+        </div>
+        <div class="form-group">
+          <label>用户名 *</label>
+          <input v-model="userForm.username" type="text" placeholder="请输入用户名">
+        </div>
+        <div class="form-group">
+          <label>密码 *</label>
+          <input v-model="userForm.password" type="password" placeholder="至少 6 位">
+        </div>
+        <div class="form-group">
+          <label class="checkbox-label">
+            <input type="checkbox" v-model="userForm.is_admin" style="width: 16px; height: 16px;">
+            管理员权限
+          </label>
+        </div>
+        <div style="margin-top: 20px; display: flex; gap: 12px; justify-content: flex-end;">
+          <button class="action-btn" style="padding: 8px 16px;" @click="showUserModal = false">取消</button>
+          <button class="btn btn-primary" style="width: auto; padding: 8px 24px;" @click="createUser">创建</button>
+        </div>
+      </div>
+    </div>
+
+    <!-- 修改密码弹窗 -->
+    <div v-if="showPasswordModal" class="modal-overlay" @click.self="showPasswordModal = false">
+      <div class="modal-content" style="width: 400px;">
+        <div class="modal-header">
+          <h3>修改密码 - {{ passwordTarget?.username }}</h3>
+          <button class="modal-close" @click="showPasswordModal = false">&times;</button>
+        </div>
+        <div class="form-group">
+          <label>新密码</label>
+          <input v-model="newPassword" type="password" placeholder="至少 6 位">
+        </div>
+        <div style="margin-top: 20px; display: flex; gap: 12px; justify-content: flex-end;">
+          <button class="action-btn" style="padding: 8px 16px;" @click="showPasswordModal = false">取消</button>
+          <button class="btn btn-primary" style="width: auto; padding: 8px 24px;" @click="changePassword">确认</button>
+        </div>
+      </div>
+    </div>
+
     <!-- 服务器环境编辑弹窗 -->
     <div v-if="showServerModal" class="modal-overlay" @click.self="showServerModal = false">
       <div class="modal-content">
@@ -449,7 +532,15 @@ const showLogin = inject('showLogin')
 const getToken = inject('getToken')
 const isLoggedIn = inject('isLoggedIn')
 const isAdmin = inject('isAdmin')
-const tab = ref('servers')
+const tab = ref('users')
+
+// 用户管理
+const users = ref([])
+const showUserModal = ref(false)
+const userForm = ref({ username: '', password: '', is_admin: false })
+const showPasswordModal = ref(false)
+const passwordTarget = ref(null)
+const newPassword = ref('')
 
 // 带认证的 fetch 封装
 const authFetch = (url, options = {}) => {
@@ -486,7 +577,7 @@ onMounted(async () => {
 })
 
 const loadData = async () => {
-  const [appsRes, schemesRes, serversRes, branchesRes, buildRes, uploadRes, configRes, versionsRes] = await Promise.all([
+  const [appsRes, schemesRes, serversRes, branchesRes, buildRes, uploadRes, configRes, versionsRes, usersRes] = await Promise.all([
     authFetch('/api/config/apps'),
     authFetch('/api/config/schemes'),
     authFetch('/api/config/servers'),
@@ -495,6 +586,7 @@ const loadData = async () => {
     authFetch('/api/config/upload'),
     authFetch('/api/config'),
     authFetch('/api/config/versions'),
+    authFetch('/api/users'),
   ])
   apps.value = await appsRes.json()
   schemes.value = await schemesRes.json()
@@ -504,6 +596,88 @@ const loadData = async () => {
   uploadConfig.value = await uploadRes.json()
   jsonContent.value = JSON.stringify(await configRes.json(), null, 2)
   versions.value = await versionsRes.json()
+  if (usersRes.ok) users.value = await usersRes.json()
+}
+
+// 用户管理
+const openUserModal = () => {
+  userForm.value = { username: '', password: '', is_admin: false }
+  showUserModal.value = true
+}
+
+const createUser = async () => {
+  if (!userForm.value.username || !userForm.value.password) {
+    alert('请填写用户名和密码')
+    return
+  }
+  try {
+    const res = await authFetch('/api/users', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify(userForm.value),
+    })
+    if (!res.ok) {
+      const err = await res.json()
+      throw new Error(err.detail || '创建失败')
+    }
+    showUserModal.value = false
+    await loadData()
+  } catch (e) {
+    alert('创建失败: ' + e.message)
+  }
+}
+
+const openPasswordModal = (u) => {
+  passwordTarget.value = u
+  newPassword.value = ''
+  showPasswordModal.value = true
+}
+
+const changePassword = async () => {
+  if (!newPassword.value || newPassword.value.length < 6) {
+    alert('密码至少 6 位')
+    return
+  }
+  try {
+    const res = await authFetch(`/api/users/${passwordTarget.value.id}/password`, {
+      method: 'PUT',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ password: newPassword.value }),
+    })
+    if (!res.ok) throw new Error('修改失败')
+    showPasswordModal.value = false
+    alert('密码已更新')
+  } catch (e) {
+    alert('修改失败: ' + e.message)
+  }
+}
+
+const toggleUserRole = async (u) => {
+  try {
+    const res = await authFetch(`/api/users/${u.id}/role`, {
+      method: 'PUT',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ is_admin: !u.is_admin }),
+    })
+    if (!res.ok) throw new Error('操作失败')
+    await loadData()
+  } catch (e) {
+    alert('操作失败: ' + e.message)
+  }
+}
+
+const deleteUser = async (u) => {
+  if (!confirm(`确定删除用户「${u.username}」？`)) return
+  try {
+    const res = await authFetch(`/api/users/${u.id}`, { method: 'DELETE' })
+    if (!res.ok) {
+      const err = await res.json()
+      throw new Error(err.detail || '删除失败')
+    }
+    await loadData()
+  } catch (e) {
+    alert('删除失败: ' + e.message)
+  }
 }
 
 // 服务器环境管理