feat: add search clear functionality and improve search input styling

webapp/src/lib/i18n.ts

@@ -546,6 +546,8 @@ const messages: Record<Locale, Record<string, string>> = {
     txt_save_profile_failed: "Save profile failed",
     txt_search_sends: "Search sends...",
     txt_search_your_secure_vault: "Search your secure vault...",
+    txt_clear_search: "Clear search",
+    txt_clear_search_esc: "Clear search (Esc)",
     txt_sort: "Sort",
     txt_sort_last_edited: "Modified",
     txt_sort_created: "Created",
@@ -872,6 +874,8 @@ const zhCNOverrides: Record<string, string> = {
   txt_loading_nodewarden: '正在加载 NodeWarden...',
   txt_search_sends: '搜索发送...',
   txt_search_your_secure_vault: '搜索你的密码库...',
+  txt_clear_search: '清空搜索',
+  txt_clear_search_esc: '清空搜索（Esc）',
   txt_refresh: '刷新',
   txt_sync: '同步',
   txt_sync_vault: '同步',