refactor(admin): 接入 PasswordInput，删除分类改用 Modal 确认

- 登录弹窗与系统改密统一用 @stash/ui 的 PasswordInput（改密页补上显隐切换）
- 删除分类不再用 window.confirm，改用 Modal + 危险按钮（组件库推荐的组合）
- 删除页面私有的 PasswordInput 组件与 .password-field 样式

stash-web/src/components/auth/LoginDialog.tsx

@@ -1,7 +1,6 @@
-import { Button, FormField, Icon, Modal, Notice, Space, Text } from '@stash/ui'
+import { Button, FormField, Icon, Modal, Notice, PasswordInput, Space, Text } from '@stash/ui'
 import { useEffect, useState } from 'react'
 import { login, setup, type SessionState } from '../../auth'
-import { PasswordInput } from './PasswordInput'
 
 /**
  * 登录弹窗：首次使用显示「设置密码 + 确认」，之后只显示密码。
@@ -88,10 +87,13 @@ export function LoginDialog({ open, hasAdmin, onClose, onSuccess }: LoginDialogP
           <PasswordInput
             id="login-password"
             placeholder="输入密码"
+            autoComplete={isSetup ? 'new-password' : 'current-password'}
             value={password}
             autoFocus
-            onChange={setPassword}
-            onEnter={() => void submit()}
+            onChange={(event) => setPassword(event.target.value)}
+            onKeyDown={(event) => {
+              if (event.key === 'Enter') void submit()
+            }}
           />
         </FormField>
 
@@ -100,9 +102,12 @@ export function LoginDialog({ open, hasAdmin, onClose, onSuccess }: LoginDialogP
             <PasswordInput
               id="login-confirm"
               placeholder="再输入一次"
+              autoComplete="new-password"
               value={confirm}
-              onChange={setConfirm}
-              onEnter={() => void submit()}
+              onChange={(event) => setConfirm(event.target.value)}
+              onKeyDown={(event) => {
+                if (event.key === 'Enter') void submit()
+              }}
             />
           </FormField>
         )}