refactor: 统一剪贴板复制功能到 useClipboard 组合式函数

将各个组件和视图中重复的剪贴板复制逻辑提取到 useClipboard 组合式函数。
增加 showToast 参数支持静默复制，减少代码重复，提高维护性。

frontend/src/views/admin/ModelManagement.vue

@@ -713,6 +713,7 @@ import ProviderModelFormDialog from '@/features/providers/components/ProviderMod
 import type { Model } from '@/api/endpoints'
 import { useToast } from '@/composables/useToast'
 import { useConfirm } from '@/composables/useConfirm'
+import { useClipboard } from '@/composables/useClipboard'
 import { useRowClick } from '@/composables/useRowClick'
 import { parseApiError } from '@/utils/errorParser'
 import {
@@ -743,6 +744,7 @@ import { getProvidersSummary } from '@/api/endpoints/providers'
 import { getAllCapabilities, type CapabilityDefinition } from '@/api/endpoints'
 
 const { success, error: showError } = useToast()
+const { copyToClipboard } = useClipboard()
 
 // 状态
 const loading = ref(false)
@@ -1066,16 +1068,6 @@ function handleRowClick(event: MouseEvent, model: GlobalModelResponse) {
   selectModel(model)
 }
 
-// 复制到剪贴板
-async function copyToClipboard(text: string) {
-  try {
-    await navigator.clipboard.writeText(text)
-    success('已复制')
-  } catch {
-    showError('复制失败')
-  }
-}
-
 async function selectModel(model: GlobalModelResponse) {
   selectedModel.value = model
   detailTab.value = 'basic'