feat(frontend): polish connection tree and terminal groups

Add explorer-style tree search in the connections view with
match-path expansion, clearer count highlighting, and a refined
sidebar header layout.

Improve terminal tab grouping by keeping new sessions appended
within their server group, highlighting the active group, and
deduplicating broadcast actions to send commands once per server.

packages/frontend/src/locales/en-US.json

@@ -1315,10 +1315,10 @@
     "copied": "Copied to clipboard",
     "copyFailed": "Copy failed",
     "actions": {
-      "sendToAllSessions": "Send to All Sessions"
+      "sendToAllSessions": "Send to All Servers"
     },
     "notifications": {
-      "sentToAllSessions": "Command sent to {count} sessions.",
+      "sentToAllSessions": "Command sent to {count} servers.",
       "noActiveSshSessions": "No active SSH sessions to send command to."
     }
   },
@@ -1356,10 +1356,10 @@
       "clickToEditTag": "Click to edit tag name"
     },
     "actions": {
-      "sendToAllSessions": "Send to All Sessions"
+      "sendToAllSessions": "Send to All Servers"
     },
     "notifications": {
-      "sentToAllSessions": "Command sent to {count} sessions.",
+      "sentToAllSessions": "Command sent to {count} servers.",
       "noActiveSshSessions": "No active SSH sessions to send command to."
     }
   },

packages/frontend/src/locales/ja-JP.json

@@ -60,10 +60,10 @@
         "loading": "ロード中...",
         "searchPlaceholder": "履歴を検索...",
         "actions": {
-          "sendToAllSessions": "すべてのセッションに送信"
+          "sendToAllSessions": "すべてのサーバーに送信"
         },
         "notifications": {
-          "sentToAllSessions": "コマンドは {count} 個のセッションに送信されました。",
+          "sentToAllSessions": "コマンドは {count} 台のサーバーに送信されました。",
           "noActiveSshSessions": "コマンドを送信するアクティブな SSH セッションはありません。"
         }
   },
@@ -730,13 +730,13 @@
         "sortByUsage": "使用頻度",
         "usageCount": "使用回数",
         "actions": {
-          "sendToAllSessions": "すべてのセッションに送信"
+          "sendToAllSessions": "すべてのサーバーに送信"
         },
         "notifications": {
-          "sentToAllSessions": "コマンドは {count} 個のセッションに送信されました。",
+          "sentToAllSessions": "コマンドは {count} 台のサーバーに送信されました。",
           "noActiveSshSessions": "コマンドを送信するアクティブな SSH セッションはありません。"
         }
-  },
+      },
   "remoteDesktopModal": {
         "errors": {
             "clientError": "クライアントエラー",

packages/frontend/src/locales/zh-CN.json

@@ -1319,10 +1319,10 @@
     "copied": "已复制到剪贴板",
     "copyFailed": "复制失败",
     "actions": {
-      "sendToAllSessions": "发送到全部会话"
+      "sendToAllSessions": "发送到全部服务器"
     },
     "notifications": {
-      "sentToAllSessions": "指令已发送到 {count} 个会话。",
+      "sentToAllSessions": "指令已发送到 {count} 台服务器。",
       "noActiveSshSessions": "没有活动的 SSH 会话可发送指令。"
     }
   },
@@ -1360,10 +1360,10 @@
       "clickToEditTag": "点击编辑标签名称"
     },
     "actions": {
-      "sendToAllSessions": "发送到全部会话"
+      "sendToAllSessions": "发送到全部服务器"
     },
     "notifications": {
-      "sentToAllSessions": "指令已发送到 {count} 个会话。",
+      "sentToAllSessions": "指令已发送到 {count} 台服务器。",
       "noActiveSshSessions": "没有活动的 SSH 会话可发送指令。"
     }
   },