feat(push,terminal): 推送搜索历史5条与终端中间搜索

推送页独立 combobox 历史（MySQL push_search，上限5）；终端空态搜索回中间卡片，右侧栏仅列表。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/composables/push/usePushServers.ts

@@ -1,14 +1,45 @@
 import { ref, computed, type Ref } from 'vue'
 import { categoryDisplayLabel } from '@/composables/useServerCategories'
+import { useServerSearchHistory } from '@/composables/useServerSearchHistory'
 import { fetchPagePerPage } from '@/utils/paginatedFetch'
 import type { PushServerItem } from './types'
 
+const PUSH_SEARCH_HISTORY = 5
+
 export function usePushServers(pushStatus: Ref<Record<number, string>>) {
   const servers = ref<PushServerItem[]>([])
   const serversLoading = ref(false)
   const serverSearch = ref('')
   const selectedIds = ref<Set<number>>(new Set())
 
+  const { items: pushSearchHistory, loadHistoryOnly, record: recordPushSearch } =
+    useServerSearchHistory('push')
+
+  const serverSearchHistory = computed(() =>
+    pushSearchHistory.value.slice(0, PUSH_SEARCH_HISTORY),
+  )
+
+  function commitServerSearch() {
+    void recordPushSearch(serverSearch.value)
+  }
+
+  function onServerSearchUpdate(val: string | null) {
+    serverSearch.value = val ?? ''
+    if (val == null || val === '') {
+      void recordPushSearch('')
+      return
+    }
+    const picked = String(val).trim()
+    if (pushSearchHistory.value.includes(picked)) {
+      serverSearch.value = picked
+      void recordPushSearch(picked)
+    }
+  }
+
+  async function loadSearchHistory() {
+    await loadHistoryOnly()
+  }
+
   let refreshTimer: ReturnType<typeof setInterval> | null = null
 
   async function loadServers(silent = false) {
@@ -113,12 +144,16 @@ export function usePushServers(pushStatus: Ref<Record<number, string>>) {
     servers,
     serversLoading,
     serverSearch,
+    serverSearchHistory,
     selectedIds,
     pushStatus,
     filteredServers,
     selectAll,
     serversByCategory,
     loadServers,
+    loadSearchHistory,
+    commitServerSearch,
+    onServerSearchUpdate,
     startAutoRefresh,
     stopAutoRefresh,
     isCategoryAllSelected,