refactor: 使用 DropdownMenu 组件重构模型测试按钮

- 新增 DropdownMenu 组件系列（DropdownMenu, DropdownMenuTrigger, DropdownMenuContent, DropdownMenuItem）
- 重构 ModelsTab 中的格式选择菜单，替换原有的手动实现
- 移除 handleClickOutside 等手动管理菜单状态的代码

frontend/src/components/ui/dropdown-menu/DropdownMenu.vue

@@ -0,0 +1,28 @@
+<script setup lang="ts">
+import { DropdownMenuRoot } from 'radix-vue'
+
+interface Props {
+  defaultOpen?: boolean
+  open?: boolean
+  modal?: boolean
+}
+
+withDefaults(defineProps<Props>(), {
+  modal: true
+})
+
+defineEmits<{
+  'update:open': [value: boolean]
+}>()
+</script>
+
+<template>
+  <DropdownMenuRoot
+    :default-open="defaultOpen"
+    :open="open"
+    :modal="modal"
+    @update:open="$emit('update:open', $event)"
+  >
+    <slot />
+  </DropdownMenuRoot>
+</template>

frontend/src/components/ui/dropdown-menu/DropdownMenuContent.vue

@@ -0,0 +1,52 @@
+<script setup lang="ts">
+import {
+  DropdownMenuContent as DropdownMenuContentPrimitive,
+  DropdownMenuPortal
+} from 'radix-vue'
+import { cn } from '@/lib/utils'
+import { computed } from 'vue'
+
+interface Props {
+  class?: string
+  sideOffset?: number
+  side?: 'top' | 'right' | 'bottom' | 'left'
+  align?: 'start' | 'center' | 'end'
+  alignOffset?: number
+  avoidCollisions?: boolean
+  forceMount?: boolean
+}
+
+const props = withDefaults(defineProps<Props>(), {
+  class: undefined,
+  sideOffset: 4,
+  side: 'bottom',
+  align: 'start',
+  alignOffset: 0,
+  avoidCollisions: true
+})
+
+const contentClass = computed(() =>
+  cn(
+    'z-[200] min-w-[8rem] overflow-hidden rounded-xl border border-border bg-popover p-1 text-popover-foreground shadow-lg',
+    'data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0 data-[state=closed]:zoom-out-95 data-[state=open]:zoom-in-95',
+    'data-[side=bottom]:slide-in-from-top-2 data-[side=left]:slide-in-from-right-2 data-[side=right]:slide-in-from-left-2 data-[side=top]:slide-in-from-bottom-2',
+    props.class
+  )
+)
+</script>
+
+<template>
+  <DropdownMenuPortal>
+    <DropdownMenuContentPrimitive
+      :class="contentClass"
+      :side-offset="sideOffset"
+      :side="side"
+      :align="align"
+      :align-offset="alignOffset"
+      :avoid-collisions="avoidCollisions"
+      :force-mount="forceMount"
+    >
+      <slot />
+    </DropdownMenuContentPrimitive>
+  </DropdownMenuPortal>
+</template>

frontend/src/components/ui/dropdown-menu/DropdownMenuItem.vue

@@ -0,0 +1,35 @@
+<script setup lang="ts">
+import { DropdownMenuItem as DropdownMenuItemPrimitive } from 'radix-vue'
+import { cn } from '@/lib/utils'
+import { computed } from 'vue'
+
+interface Props {
+  class?: string
+  disabled?: boolean
+}
+
+const props = defineProps<Props>()
+
+defineEmits<{
+  select: [event: Event]
+}>()
+
+const itemClass = computed(() =>
+  cn(
+    'relative flex cursor-pointer select-none items-center rounded-lg px-3 py-1.5 text-sm outline-none',
+    'hover:bg-accent focus:bg-accent focus:text-accent-foreground',
+    'transition-colors data-[disabled]:pointer-events-none data-[disabled]:opacity-50',
+    props.class
+  )
+)
+</script>
+
+<template>
+  <DropdownMenuItemPrimitive
+    :class="itemClass"
+    :disabled="disabled"
+    @select="$emit('select', $event)"
+  >
+    <slot />
+  </DropdownMenuItemPrimitive>
+</template>

frontend/src/components/ui/dropdown-menu/DropdownMenuTrigger.vue

@@ -0,0 +1,22 @@
+<script setup lang="ts">
+import { DropdownMenuTrigger as DropdownMenuTriggerPrimitive } from 'radix-vue'
+
+interface Props {
+  asChild?: boolean
+  disabled?: boolean
+}
+
+withDefaults(defineProps<Props>(), {
+  asChild: false,
+  disabled: false
+})
+</script>
+
+<template>
+  <DropdownMenuTriggerPrimitive
+    :as-child="asChild"
+    :disabled="disabled"
+  >
+    <slot />
+  </DropdownMenuTriggerPrimitive>
+</template>

frontend/src/components/ui/dropdown-menu/index.ts

@@ -0,0 +1,4 @@
+export { default as DropdownMenu } from './DropdownMenu.vue'
+export { default as DropdownMenuTrigger } from './DropdownMenuTrigger.vue'
+export { default as DropdownMenuContent } from './DropdownMenuContent.vue'
+export { default as DropdownMenuItem } from './DropdownMenuItem.vue'

frontend/src/components/ui/index.ts

@@ -70,3 +70,6 @@ export { Tooltip, TooltipContent, TooltipProvider, TooltipTrigger } from './tool
 export { default as Collapsible } from './collapsible.vue'
 export { default as CollapsibleTrigger } from './collapsible-trigger.vue'
 export { default as CollapsibleContent } from './collapsible-content.vue'
+
+// DropdownMenu 下拉菜单系列
+export { DropdownMenu, DropdownMenuTrigger, DropdownMenuContent, DropdownMenuItem } from './dropdown-menu'