feat: batch delete preview, FlushDB, search history, cancel scan

- P2-7: KeyList batch delete preview dialog (max 100 keys shown)
- P2-11: StatusView FlushDB with double confirmation (type FLUSHDB)
- P2-12: KeyList search history (localStorage, max 20, dropdown on focus)
- P2-13: key store cancelScan() + KeyList cancel button
- i18n keys for all features (zh-CN + en)

src/stores/key.ts

@@ -26,6 +26,7 @@ export const useKeyStore = defineStore('key', () => {
   const loading = ref(false)
   const scanCursor = ref('0')
   const hasMore = ref(false)
+  const scanAborted = ref(false)
   const pattern = ref('*')
   const useTree = ref(false)
   const currentDb = ref(0)
@@ -71,11 +72,22 @@ export const useKeyStore = defineStore('key', () => {
     return root
   }
 
+  function cancelScan() {
+    scanAborted.value = true
+  }
+
   async function scanKeys(connId: string, cursor: string = '0', reset: boolean = false) {
+    if (scanAborted.value) {
+      scanAborted.value = false
+      loading.value = false
+      return
+    }
+
     if (reset) {
       scanCursor.value = '0'
       keys.value = []
       hasMore.value = false
+      scanAborted.value = false
     }
 
     loading.value = true
@@ -180,7 +192,7 @@ export const useKeyStore = defineStore('key', () => {
 
   return {
     keys, treeKeys, selectedKey, selectedType, selectedTTL, keyData,
-    loading, scanCursor, hasMore, pattern, useTree, currentDb,
-    scanKeys, loadKeyTypeAndTTL, loadKeyData, selectDb,
+    loading, scanCursor, hasMore, scanAborted, pattern, useTree, currentDb,
+    scanKeys, cancelScan, loadKeyTypeAndTTL, loadKeyData, selectDb,
   }
 })