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/stores/session/actions/sessionActions.ts

@@ -15,6 +15,8 @@ import { createStatusMonitorManager, type StatusMonitorDependencies } from '../.
 import { createDockerManager, type DockerManagerDependencies } from '../../../composables/useDockerManager';
 import { registerSshSuspendHandlers } from './sshSuspendActions'; 
 
+const SESSION_ORDER_STORAGE_KEY = 'sessionOrder';
+
 
 // --- 辅助函数 (特定于此模块的 actions) ---
 const findConnectionInfo = (connectionId: number | string, connectionsStore: ReturnType<typeof useConnectionsStore>): ConnectionInfo | undefined => {
@@ -33,6 +35,75 @@ const getNextTerminalIndex = (connectionId: string): number => {
   return maxTerminalIndex + 1;
 };
 
+const getOrderedSessionIds = (): string[] => {
+  const savedOrderStr = localStorage.getItem(SESSION_ORDER_STORAGE_KEY);
+  let savedOrder: string[] = [];
+
+  if (savedOrderStr) {
+    try {
+      savedOrder = JSON.parse(savedOrderStr);
+    } catch (error) {
+      console.error('[SessionActions] 解析 sessionOrder 失败，回退到创建顺序。', error);
+      savedOrder = [];
+    }
+  }
+
+  const sessionList = Array.from(sessions.value.values());
+
+  if (savedOrder.length === 0) {
+    return sessionList
+      .sort((a, b) => a.createdAt - b.createdAt)
+      .map((session) => session.sessionId);
+  }
+
+  return sessionList
+    .sort((a, b) => {
+      const indexA = savedOrder.indexOf(a.sessionId);
+      const indexB = savedOrder.indexOf(b.sessionId);
+      if (indexA === -1 && indexB === -1) return a.createdAt - b.createdAt;
+      if (indexA === -1) return 1;
+      if (indexB === -1) return -1;
+      return indexA - indexB;
+    })
+    .map((session) => session.sessionId);
+};
+
+const saveOrderedSessionIds = (sessionIds: string[]) => {
+  localStorage.setItem(SESSION_ORDER_STORAGE_KEY, JSON.stringify(sessionIds));
+};
+
+const insertSessionIdIntoOrder = (sessionId: string, connectionId: string) => {
+  const orderedSessionIds = getOrderedSessionIds();
+  const nextOrder = [...orderedSessionIds];
+
+  if (nextOrder.includes(sessionId)) {
+    return;
+  }
+
+  let insertionIndex = nextOrder.length;
+  for (let index = nextOrder.length - 1; index >= 0; index -= 1) {
+    const orderedSession = sessions.value.get(nextOrder[index]);
+    if (orderedSession?.connectionId === connectionId) {
+      insertionIndex = index + 1;
+      break;
+    }
+  }
+
+  nextOrder.splice(insertionIndex, 0, sessionId);
+  saveOrderedSessionIds(nextOrder);
+};
+
+const replaceSessionIdInOrder = (previousSessionId: string, nextSessionId: string) => {
+  const orderedSessionIds = getOrderedSessionIds();
+  const updatedOrder = orderedSessionIds.map((sessionId) => (sessionId === previousSessionId ? nextSessionId : sessionId));
+  saveOrderedSessionIds(Array.from(new Set(updatedOrder)));
+};
+
+const removeSessionIdFromOrder = (sessionId: string) => {
+  const orderedSessionIds = getOrderedSessionIds().filter((orderedSessionId) => orderedSessionId !== sessionId);
+  saveOrderedSessionIds(orderedSessionIds);
+};
+
 // --- Actions ---
 export const openNewSession = (
     connectionOrId: ConnectionInfo | number | string,
@@ -128,6 +199,7 @@ export const openNewSession = (
   const newSessionsMap = new Map(sessions.value);
   newSessionsMap.set(newSessionId, newSession);
   sessions.value = newSessionsMap;
+  insertSessionIdIntoOrder(newSessionId, dbConnId);
   activeSessionId.value = newSessionId;
   console.log(`[SessionActions] 已创建新会话实例: ${newSessionId} for connection ${dbConnId} (terminal #${terminalIndex})`);
 
@@ -157,6 +229,7 @@ export const openNewSession = (
 
         currentSessions.set(backendSID, sessionToUpdate);
         sessions.value = currentSessions;
+        replaceSessionIdInOrder(originalFrontendSessionIdForHandler, backendSID);
 
         if (activeSessionId.value === originalFrontendSessionIdForHandler) {
           activeSessionId.value = backendSID;
@@ -253,6 +326,7 @@ export const closeSession = (sessionId: string) => {
   const newSessionsMap = new Map(sessions.value);
   newSessionsMap.delete(sessionId);
   sessions.value = newSessionsMap;
+  removeSessionIdFromOrder(sessionId);
   console.log(`[SessionActions] 已从 Map 中移除会话: ${sessionId}`);
 
   // 3. 切换活动标签页
@@ -333,5 +407,6 @@ export const cleanupAllSessions = () => {
     newSessionsMap.clear();
     sessions.value = newSessionsMap;
   }
+  saveOrderedSessionIds([]);
   activeSessionId.value = null;
 };