Please provide the code changes or file diffs you would like me to summarize.

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "java.compile.nullAnalysis.mode": "automatic"
+}

Makefile

@@ -1,14 +1,15 @@
-.PHONY: help build up down restart logs ps
+.PHONY: help build up up-build down restart logs ps
 
 COMPOSE_FILE := docker/docker-compose.yml
 COMPOSE := docker compose -f $(COMPOSE_FILE)
 
 help:
 	@printf "Available targets:\n"
-	@printf "  make build    Build Docker images\n"
-	@printf "  make up       Build and start services in background\n"
+	@printf "  make build      Build Docker images (with cache)\n"
+	@printf "  make up         Start services (NO rebuild, reuse existing image)\n"
+	@printf "  make up-build   Rebuild image then start (use after code changes)\n"
 	@printf "  make down       Stop and remove services\n"
-	@printf "  make restart  Restart services\n"
+	@printf "  make restart    Restart services without rebuild\n"
 	@printf "  make logs       Follow service logs\n"
 	@printf "  make ps         Show service status\n"
 	@printf "  Note: do not use 'docker compose down -v' in daily usage (it removes persistent volumes)\n"
@@ -16,7 +17,12 @@ help:
 build:
 	$(COMPOSE) build
 
+# 日常启动：直接用已有镜像，不重新构建（秒启动）
 up:
+	$(COMPOSE) up -d
+
+# 代码有改动时使用：重新构建镜像再启动
+up-build:
 	$(COMPOSE) build
 	$(COMPOSE) up -d
 
@@ -24,8 +30,7 @@ down:
 	$(COMPOSE) down
 
 restart:
-	$(COMPOSE) down
-	$(COMPOSE) up -d
+	$(COMPOSE) restart
 
 logs:
 	$(COMPOSE) logs -f

backend/src/main/java/com/sshmanager/service/SftpService.java

@@ -25,7 +25,7 @@ import java.util.concurrent.atomic.AtomicLong;
 @Service
 public class SftpService {
 
-    private ExecutorService executorService = Executors.newFixedThreadPool(2);
+    private ExecutorService executorService = Executors.newCachedThreadPool();
 
     public void setExecutorService(ExecutorService executorService) {
         this.executorService = executorService;
@@ -231,8 +231,9 @@ public class SftpService {
     }
 
     /**
-     * Transfer a single file from source session to target session (streaming, no full file in memory).
-     * Fails if sourcePath is a directory.
+     * Transfer a file or directory from source session to target session.
+     * If sourcePath is a directory, transfers recursively (the source directory itself is
+     * recreated under targetPath — "plan A" / scp -r behaviour).
      */
     public void transferRemote(SftpSession source, String sourcePath, SftpSession target, String targetPath)
             throws Exception {
@@ -246,8 +247,161 @@ public class SftpService {
                                TransferProgressListener progressListener) throws Exception {
         SftpATTRS attrs = source.getChannel().stat(sourcePath);
         if (attrs.isDir()) {
-            throw new IllegalArgumentException("Source path is a directory; only single file transfer is supported");
+            final long totalBytes = calculateTotalSize(source, sourcePath);
+            if (progressListener != null) {
+                progressListener.onStart(totalBytes);
             }
+            AtomicLong transferred = new AtomicLong(0);
+            transferDirectoryRemote(source, sourcePath, target, targetPath, totalBytes, transferred, progressListener);
+        } else {
+            String finalTargetPath = targetPath;
+            try {
+                SftpATTRS targetAttrs = target.getChannel().stat(targetPath);
+                if (targetAttrs.isDir()) {
+                    String fileName = sourcePath.contains("/") ? sourcePath.substring(sourcePath.lastIndexOf('/') + 1) : sourcePath;
+                    finalTargetPath = targetPath.endsWith("/") ? targetPath + fileName : targetPath + "/" + fileName;
+                }
+            } catch (SftpException e) {
+                if (targetPath.endsWith("/")) {
+                    String fileName = sourcePath.contains("/") ? sourcePath.substring(sourcePath.lastIndexOf('/') + 1) : sourcePath;
+                    finalTargetPath = targetPath + fileName;
+                }
+            }
+            transferSingleFileRemote(source, sourcePath, target, finalTargetPath, progressListener);
+        }
+    }
+
+    /** Recursively calculate total byte size of all files under a remote path. */
+    private long calculateTotalSize(SftpSession session, String path) throws Exception {
+        SftpATTRS attrs = session.getChannel().stat(path);
+        if (!attrs.isDir()) {
+            return attrs.getSize();
+        }
+        long total = 0;
+        Vector<?> entries = session.getChannel().ls(path);
+        for (Object obj : entries) {
+            ChannelSftp.LsEntry entry = (ChannelSftp.LsEntry) obj;
+            String name = entry.getFilename();
+            if (".".equals(name) || "..".equals(name)) continue;
+            String childPath = path.endsWith("/") ? path + name : path + "/" + name;
+            total += calculateTotalSize(session, childPath);
+        }
+        return total;
+    }
+
+    /** Recursively create a directory and its parents on a remote session (mkdir -p). */
+    private void mkdirRecursive(SftpSession session, String path) throws Exception {
+        try {
+            SftpATTRS attrs = session.getChannel().stat(path);
+            if (attrs.isDir()) return;
+            throw new IllegalStateException("Path exists but is not a directory: " + path);
+        } catch (SftpException e) {
+            if (e.id != ChannelSftp.SSH_FX_NO_SUCH_FILE) throw e;
+        }
+        int slash = path.lastIndexOf('/');
+        if (slash > 0) {
+            mkdirRecursive(session, path.substring(0, slash));
+        }
+        try {
+            session.getChannel().mkdir(path);
+        } catch (SftpException e) {
+            // Another thread may have created it concurrently; SSH_FX_FAILURE is returned in that case
+            if (e.id != ChannelSftp.SSH_FX_FAILURE) throw e;
+        }
+    }
+
+    /**
+     * Recursively transfer a directory.
+     * The source directory name is recreated under targetParentPath (plan A / scp -r behaviour).
+     */
+    private void transferDirectoryRemote(SftpSession source,
+                                          String sourceDirPath,
+                                          SftpSession target,
+                                          String targetParentPath,
+                                          long totalBytes,
+                                          AtomicLong transferred,
+                                          TransferProgressListener progressListener) throws Exception {
+        String dirName = sourceDirPath.contains("/")
+                ? sourceDirPath.substring(sourceDirPath.lastIndexOf('/') + 1)
+                : sourceDirPath;
+        String targetDirPath = targetParentPath.endsWith("/")
+                ? targetParentPath + dirName
+                : targetParentPath + "/" + dirName;
+
+        mkdirRecursive(target, targetDirPath);
+
+        Vector<?> entries = source.getChannel().ls(sourceDirPath);
+        for (Object obj : entries) {
+            ChannelSftp.LsEntry entry = (ChannelSftp.LsEntry) obj;
+            String name = entry.getFilename();
+            if (".".equals(name) || "..".equals(name)) continue;
+            String childSourcePath = sourceDirPath.endsWith("/")
+                    ? sourceDirPath + name
+                    : sourceDirPath + "/" + name;
+            if (entry.getAttrs().isDir()) {
+                transferDirectoryRemote(source, childSourcePath, target, targetDirPath,
+                        totalBytes, transferred, progressListener);
+            } else {
+                String childTargetPath = targetDirPath + "/" + name;
+                transferSingleFileAccumulating(source, childSourcePath,
+                        target, childTargetPath, totalBytes, transferred, progressListener);
+            }
+        }
+    }
+
+    /** Stream a single file and accumulate progress into a shared counter (used during directory transfer). */
+    private void transferSingleFileAccumulating(SftpSession source,
+                                                 String sourcePath,
+                                                 SftpSession target,
+                                                 String targetFilePath,
+                                                 long totalBytes,
+                                                 AtomicLong transferred,
+                                                 TransferProgressListener progressListener) throws Exception {
+        final int pipeBufferSize = 65536;
+        PipedOutputStream pos = new PipedOutputStream();
+        PipedInputStream pis = new PipedInputStream(pos, pipeBufferSize);
+
+        Future<?> putFuture = executorService.submit(() -> {
+            try {
+                target.getChannel().put(pis, targetFilePath, new SftpProgressMonitor() {
+                    @Override public void init(int op, String src, String dest, long max) {}
+
+                    @Override
+                    public boolean count(long count) {
+                        long current = transferred.addAndGet(count);
+                        if (progressListener != null) {
+                            progressListener.onProgress(current, totalBytes);
+                        }
+                        return true;
+                    }
+
+                    @Override public void end() {}
+                }, ChannelSftp.OVERWRITE);
+            } catch (Exception e) {
+                throw new RuntimeException(e);
+            } finally {
+                try { pis.close(); } catch (Exception ignored) {}
+            }
+        });
+        try {
+            source.getChannel().get(sourcePath, pos);
+        } finally {
+            try { pos.close(); } catch (Exception ignored) {}
+        }
+        try {
+            putFuture.get();
+        } finally {
+            try { pis.close(); } catch (Exception ignored) {}
+        }
+    }
+
+    /** Transfer a single file with its own independent progress tracking. */
+    private void transferSingleFileRemote(SftpSession source,
+                                           String sourcePath,
+                                           SftpSession target,
+                                           String targetPath,
+                                           TransferProgressListener progressListener) throws Exception {
+        SftpATTRS attrs = source.getChannel().stat(sourcePath);
         final long totalBytes = attrs.getSize();
         final int pipeBufferSize = 65536;
         PipedOutputStream pos = new PipedOutputStream();
@@ -263,46 +417,36 @@ public class SftpService {
                 target.getChannel().put(pis, targetPath, new SftpProgressMonitor() {
                     @Override
                     public void init(int op, String src, String dest, long max) {
-                        if (progressListener != null) {
-                            progressListener.onStart(totalBytes);
-                        }
+                        if (progressListener != null) progressListener.onStart(totalBytes);
                     }
 
                     @Override
                     public boolean count(long count) {
                         long current = transferredBytes.addAndGet(count);
-                        if (progressListener != null) {
-                            progressListener.onProgress(current, totalBytes);
-                        }
+                        if (progressListener != null) progressListener.onProgress(current, totalBytes);
                         return true;
                     }
 
                     @Override
                     public void end() {
-                        if (progressListener != null) {
-                            progressListener.onProgress(totalBytes, totalBytes);
-                        }
+                        if (progressListener != null) progressListener.onProgress(totalBytes, totalBytes);
                     }
                 }, ChannelSftp.OVERWRITE);
             } catch (Exception e) {
                 throw new RuntimeException(e);
+            } finally {
+                try { pis.close(); } catch (Exception ignored) {}
             }
         });
         try {
             source.getChannel().get(sourcePath, pos);
         } finally {
-            try {
-                pos.close();
-            } catch (Exception ignored) {
-            }
+            try { pos.close(); } catch (Exception ignored) {}
         }
         try {
             putFuture.get();
         } finally {
-            try {
-                pis.close();
-            } catch (Exception ignored) {
-            }
+            try { pis.close(); } catch (Exception ignored) {}
         }
     }
 

frontend/src/components/SftpFileSelectorModal.tsx

@@ -0,0 +1,63 @@
+import { useState } from 'react'
+import { X } from 'lucide-react'
+import SftpPane from './SftpPane'
+import type { Connection } from '../types'
+
+export default function SftpFileSelectorModal({
+  open,
+  connection,
+  onSelect,
+  onClose,
+}: {
+  open: boolean
+  connection: Connection
+  onSelect: (path: string) => void
+  onClose: () => void
+}) {
+  const [selectedFiles, setSelectedFiles] = useState<string[]>([])
+
+  if (!open) return null
+
+  return (
+    <div
+      className="fixed inset-0 z-50 flex items-center justify-center bg-black/70 backdrop-blur-sm"
+      onClick={(e) => {
+        if (e.target === e.currentTarget) onClose()
+      }}
+    >
+      <div className="flex h-[80vh] w-[80vw] max-w-5xl flex-col overflow-hidden rounded-2xl border border-slate-700 bg-[#0d1117] shadow-2xl shadow-black/60">
+        {/* Header */}
+        <div className="flex shrink-0 items-center justify-between border-b border-slate-800 bg-slate-900 px-5 py-3.5">
+          <div>
+            <h2 className="text-sm font-semibold text-white">浏览远程文件</h2>
+            <p className="mt-0.5 text-xs text-slate-400">
+              来源：<span className="text-purple-400">{connection.name}</span>
+              　·　单击选中，双击进入目录，点击底部"确认选择"完成
+            </p>
+          </div>
+          <button
+            className="rounded-xl p-2 text-slate-500 transition hover:bg-slate-800 hover:text-white"
+            onClick={onClose}
+            aria-label="关闭"
+          >
+            <X size={18} />
+          </button>
+        </div>
+
+        {/* SftpPane in selection mode */}
+        <div className="min-h-0 flex-1 overflow-hidden">
+          <SftpPane
+            connection={connection}
+            selectedFiles={selectedFiles}
+            onSelectedFilesChange={setSelectedFiles}
+            selectionMode
+            onConfirmSelection={(path) => {
+              onSelect(path)
+              onClose()
+            }}
+          />
+        </div>
+      </div>
+    </div>
+  )
+}

frontend/src/components/SftpPane.tsx

@@ -70,11 +70,16 @@ export default function SftpPane({
   selectedFiles,
   onSelectedFilesChange,
   onRefreshSignal,
+  selectionMode,
+  onConfirmSelection,
 }: {
   connection: Connection
   selectedFiles: string[]
   onSelectedFilesChange: (files: string[]) => void
   onRefreshSignal?: (refresh: () => Promise<void>) => void
+  /** When true, shows a bottom bar for path confirmation */
+  selectionMode?: boolean
+  onConfirmSelection?: (fullPath: string) => void
 }) {
   const fileInputRef = useRef<HTMLInputElement | null>(null)
   const uploadMenuRef = useRef<HTMLDivElement | null>(null)
@@ -978,6 +983,29 @@ export default function SftpPane({
         onClose={() => setCreateDirectoryModalOpen(false)}
         onSubmit={handleCreateDir}
       />
+
+      {selectionMode ? (() => {
+        const singleSelected = selectedFiles.length === 1 ? selectedFiles[0] : null
+        const confirmPath = singleSelected
+          ? joinPath(currentPath, singleSelected)
+          : currentPath
+        return (
+          <div className="shrink-0 border-t border-purple-900/50 bg-purple-950/30 px-4 py-3">
+            <div className="flex items-center gap-3">
+              <div className="min-w-0 flex-1">
+                <p className="text-xs text-slate-400">{singleSelected ? '已选择文件/文件夹' : '将选择当前目录'}</p>
+                <p className="mt-0.5 truncate font-mono text-xs text-purple-300">{confirmPath}</p>
+              </div>
+              <button
+                className="shrink-0 rounded-xl bg-purple-600 px-4 py-2 text-sm font-medium text-white transition hover:bg-purple-500"
+                onClick={() => onConfirmSelection?.(confirmPath)}
+              >
+                确认选择
+              </button>
+            </div>
+          </div>
+        )
+      })() : null}
     </div>
   )
 }

frontend/src/components/TerminalPane.tsx

@@ -142,10 +142,8 @@ export default function TerminalPane({
   }, [visible])
 
   return (
-    <div className="flex h-full flex-col overflow-hidden bg-slate-900">
-      <div className="flex-1 bg-black p-2 font-mono">
-        <div ref={containerRef} className="h-full w-full overflow-hidden rounded-2xl border border-slate-900 bg-black" />
-      </div>
+    <div className="flex h-full flex-col overflow-hidden bg-black">
+      <div ref={containerRef} className="h-full w-full overflow-hidden" />
     </div>
   )
 }

frontend/src/components/TransferCenterModal.tsx

@@ -1,6 +1,18 @@
 import { useState } from 'react'
-import { CheckCircle2, FileUp, ListTree, Monitor, RefreshCw, Server, Target, Upload, Zap } from 'lucide-react'
+import {
+  CheckCircle2,
+  FileUp,
+  FolderOpen,
+  ListTree,
+  Monitor,
+  RefreshCw,
+  Server,
+  Target,
+  Upload,
+  Zap,
+} from 'lucide-react'
 import Modal from './Modal'
+import SftpFileSelectorModal from './SftpFileSelectorModal'
 import {
   cancelRemoteTransferTask,
   createRemoteTransferTask,
@@ -8,7 +20,7 @@ import {
   subscribeUploadProgress,
   uploadFile,
 } from '../services/sftp'
-import type { Connection, TransferTaskGroup, TransferTaskItem } from '../types'
+import type { Connection, ConnectionReachabilityStatus, TransferTaskGroup, TransferTaskItem } from '../types'
 
 function aggregate(items: TransferTaskItem[]) {
   const total = items.length || 1
@@ -20,18 +32,32 @@ function aggregate(items: TransferTaskItem[]) {
   return { progress, status: status as TransferTaskGroup['status'] }
 }
 
+function StatusDot({ status }: { status: ConnectionReachabilityStatus | undefined }) {
+  if (status === 'online')
+    return <span className="h-2 w-2 shrink-0 rounded-full bg-emerald-400" title="在线" />
+  if (status === 'offline')
+    return <span className="h-2 w-2 shrink-0 rounded-full bg-red-400" title="离线" />
+  if (status === 'checking')
+    return <span className="h-2 w-2 shrink-0 animate-pulse rounded-full bg-yellow-400" title="检测中" />
+  return <span className="h-2 w-2 shrink-0 rounded-full bg-slate-600" title="未知" />
+}
+
+
+
 export default function TransferCenterModal({
   open,
   connections,
+  connectionStatuses,
   tasks,
   onClose,
   onTasksChange,
 }: {
   open: boolean
   connections: Connection[]
+  connectionStatuses: Record<number, ConnectionReachabilityStatus>
   tasks: TransferTaskGroup[]
   onClose: () => void
-  onTasksChange: (tasks: TransferTaskGroup[]) => void
+  onTasksChange: (updater: TransferTaskGroup[] | ((prev: TransferTaskGroup[]) => TransferTaskGroup[])) => void
 }) {
   const [tab, setTab] = useState<'local' | 'remote'>('local')
   const [targetIds, setTargetIds] = useState<number[]>(connections.length ? [connections[0].id] : [])
@@ -40,11 +66,13 @@ export default function TransferCenterModal({
   const [remoteSourceId, setRemoteSourceId] = useState<number>(connections[0]?.id ?? 0)
   const [remoteSourcePath, setRemoteSourcePath] = useState('/opt/app/build.tar.gz')
   const [remoteTargetPath, setRemoteTargetPath] = useState('/data/deploy/')
+  const [showBrowser, setShowBrowser] = useState(false)
 
   if (!open) return null
 
   function updateTaskGroup(groupId: string, updater: (group: TransferTaskGroup) => TransferTaskGroup) {
-    onTasksChange(tasks.map((task) => (task.id === groupId ? updater(task) : task)))
+    // Use functional update to always read latest state, avoiding stale-closure bugs in async callbacks
+    onTasksChange((prev) => prev.map((task) => (task.id === groupId ? updater(task) : task)))
   }
 
   async function handleStartLocal() {
@@ -66,7 +94,7 @@ export default function TransferCenterModal({
         message: '等待上传',
       })),
     }
-    onTasksChange([group, ...tasks])
+    onTasksChange((prev) => [group, ...prev])
 
     targetIds.forEach(async (targetId) => {
       const response = await uploadFile(targetId, localTargetPath, file, { overwrite: true })
@@ -87,7 +115,7 @@ export default function TransferCenterModal({
                   ...item,
                   progress: task.progress,
                   status: task.status,
-                  message: task.error || (task.status === 'success' ? '上传完成' : '正在传输...'),
+                  message: task.error || (task.status === 'success' ? '上传完成' : task.status === 'error' ? '上传失败' : task.status === 'cancelled' ? '已取消' : '正在传输...'),
                 }
               : item,
           )
@@ -104,10 +132,11 @@ export default function TransferCenterModal({
   async function handleStartRemote() {
     if (!remoteSourceId || targetIds.length === 0 || !remoteSourcePath.trim()) return
     const groupId = String(Date.now())
+    const sourceName = remoteSourcePath.trim().split('/').filter(Boolean).pop() || remoteSourcePath.trim()
     const group: TransferTaskGroup = {
       id: groupId,
       mode: 'REMOTE_TO_MANY',
-      title: '跨主机文件同步',
+      title: `跨主机分发 · ${sourceName}`,
       status: 'running',
       progress: 0,
       createdAt: new Date().toLocaleTimeString(),
@@ -119,7 +148,7 @@ export default function TransferCenterModal({
         message: '等待创建任务',
       })),
     }
-    onTasksChange([group, ...tasks])
+    onTasksChange((prev) => [group, ...prev])
 
     targetIds.forEach(async (targetId) => {
       const response = await createRemoteTransferTask(remoteSourceId, remoteSourcePath, targetId, remoteTargetPath)
@@ -140,7 +169,7 @@ export default function TransferCenterModal({
                   ...item,
                   progress: task.progress,
                   status: task.status,
-                  message: task.error || (task.status === 'success' ? '同步完成' : '正在同步...'),
+                  message: task.error || (task.status === 'success' ? '同步完成' : task.status === 'error' ? '同步失败' : task.status === 'cancelled' ? '已取消' : '正在同步...'),
                 }
               : item,
           )
@@ -155,16 +184,24 @@ export default function TransferCenterModal({
   }
 
   return (
+    <>
       <Modal title="文件传输中心" onClose={onClose} maxWidth="max-w-7xl">
       <div className="flex h-[74vh] flex-col overflow-hidden rounded-2xl border border-slate-800 bg-[#0d1117]">
+        {/* Tabs */}
         <div className="flex gap-8 border-b border-slate-800 bg-slate-900 px-6 pt-4">
-          <button className={`border-b-2 pb-3 text-sm font-medium ${tab === 'local' ? 'border-blue-500 text-blue-400' : 'border-transparent text-slate-400'}`} onClick={() => setTab('local')}>
+          <button
+            className={`border-b-2 pb-3 text-sm font-medium ${tab === 'local' ? 'border-blue-500 text-blue-400' : 'border-transparent text-slate-400'}`}
+            onClick={() => setTab('local')}
+          >
             <span className="flex items-center gap-2">
               <Monitor size={16} />
               本地分发到多台
             </span>
           </button>
-          <button className={`border-b-2 pb-3 text-sm font-medium ${tab === 'remote' ? 'border-purple-500 text-purple-400' : 'border-transparent text-slate-400'}`} onClick={() => setTab('remote')}>
+          <button
+            className={`border-b-2 pb-3 text-sm font-medium ${tab === 'remote' ? 'border-purple-500 text-purple-400' : 'border-transparent text-slate-400'}`}
+            onClick={() => { setTab('remote'); setShowBrowser(false) }}
+          >
             <span className="flex items-center gap-2">
               <Server size={16} />
               远程分发到多台
@@ -173,7 +210,8 @@ export default function TransferCenterModal({
         </div>
 
         <div className="flex flex-1 overflow-hidden">
-          <div className="flex flex-1 overflow-auto border-r border-slate-800 bg-slate-900/70 p-6">
+          {/* Left panel */}
+          <div className="flex flex-1 overflow-hidden border-r border-slate-800 bg-slate-900/70 p-6">
             {tab === 'local' ? (
               <div className="flex flex-1 flex-col space-y-6">
                 <label className="space-y-2">
@@ -196,10 +234,19 @@ export default function TransferCenterModal({
                 <div className="flex-1 space-y-2">
                   <span className="text-sm text-slate-300">3. 目标服务器</span>
                   <div className="rounded-2xl border border-slate-700 bg-black p-2">
-                    {connections.map((server) => (
-                      <label key={server.id} className="flex items-center gap-2 rounded-xl px-3 py-2 hover:bg-slate-800">
+                    {connections.map((server) => {
+                      const st = connectionStatuses[server.id]
+                      const isOnline = st === 'online'
+                      return (
+                        <label
+                          key={server.id}
+                          className={`flex items-center gap-2 rounded-xl px-3 py-2 ${
+                            isOnline ? 'cursor-pointer hover:bg-slate-800' : 'cursor-not-allowed opacity-40'
+                          }`}
+                        >
                           <input
                             type="checkbox"
+                            disabled={!isOnline}
                             checked={targetIds.includes(server.id)}
                             onChange={() =>
                               setTargetIds((prev) =>
@@ -207,60 +254,143 @@ export default function TransferCenterModal({
                               )
                             }
                           />
-                        <Server size={14} className="text-slate-500" />
+                          <StatusDot status={st} />
+                          <Server size={14} className={isOnline ? 'text-emerald-500' : 'text-slate-600'} />
                           <span className="text-sm text-slate-300">{server.name}</span>
                         </label>
-                    ))}
+                      )
+                    })}
                   </div>
                 </div>
-                <button className="flex w-full items-center justify-center gap-2 rounded-xl bg-blue-600 py-3 font-medium text-white transition hover:bg-blue-500" onClick={() => void handleStartLocal()}>
+                <button
+                  className={`flex w-full items-center justify-center gap-2 rounded-xl py-3 font-medium transition ${
+                    !localFiles?.length || targetIds.length === 0
+                      ? 'cursor-not-allowed bg-slate-800 text-slate-500'
+                      : 'bg-blue-600 text-white hover:bg-blue-500'
+                  }`}
+                  disabled={!localFiles?.length || targetIds.length === 0}
+                  onClick={() => void handleStartLocal()}
+                >
                   <Upload size={18} />
-                  开始分发
+                  {!localFiles?.length ? '请选择本地文件' : targetIds.length === 0 ? '请选择目标服务器' : '开始分发'}
                 </button>
               </div>
             ) : (
-              <div className="flex flex-1 gap-6">
-                <div className="flex w-1/2 flex-col gap-5 border-r border-slate-800 pr-6">
+              <div className="flex h-full flex-1 gap-6 overflow-hidden">
+                {/* Source config */}
+                <div className="flex w-1/2 shrink-0 flex-col gap-4 overflow-y-auto border-r border-slate-800 pr-6">
                   <h3 className="flex items-center gap-2 text-sm font-bold text-purple-400">
                     <Zap size={16} />
                     源配置
                   </h3>
-                  <label className="space-y-2">
+
+                  <div className="space-y-2">
+                    <div className="flex items-center gap-2">
                       <span className="text-sm text-slate-300">源服务器</span>
-                    <select className="w-full rounded-xl border border-slate-700 bg-black px-4 py-3 text-sm text-white" value={remoteSourceId} onChange={(event) => setRemoteSourceId(Number(event.target.value))}>
-                      {connections.map((server) => (
-                        <option key={server.id} value={server.id}>
-                          {server.name}
-                        </option>
-                      ))}
-                    </select>
-                  </label>
-                  <label className="flex flex-1 flex-col space-y-2">
-                    <span className="text-sm text-slate-300">源文件路径</span>
-                    <textarea className="min-h-[180px] flex-1 rounded-xl border border-slate-700 bg-black px-4 py-3 font-mono text-sm text-white" value={remoteSourcePath} onChange={(event) => setRemoteSourcePath(event.target.value)} />
-                  </label>
+                      {(() => {
+                        const st = connectionStatuses[remoteSourceId]
+                        if (st === 'online') return <span className="flex items-center gap-1 rounded-full bg-emerald-500/15 px-2 py-0.5 text-xs font-medium text-emerald-400"><span className="h-1.5 w-1.5 rounded-full bg-emerald-400" />在线</span>
+                        if (st === 'offline') return <span className="flex items-center gap-1 rounded-full bg-red-500/15 px-2 py-0.5 text-xs font-medium text-red-400"><span className="h-1.5 w-1.5 rounded-full bg-red-400" />离线</span>
+                        if (st === 'checking') return <span className="flex items-center gap-1 rounded-full bg-yellow-500/15 px-2 py-0.5 text-xs font-medium text-yellow-400"><span className="h-1.5 w-1.5 animate-pulse rounded-full bg-yellow-400" />检测中</span>
+                        return <span className="flex items-center gap-1 rounded-full bg-slate-700/60 px-2 py-0.5 text-xs font-medium text-slate-500"><span className="h-1.5 w-1.5 rounded-full bg-slate-500" />未知</span>
+                      })()}
                     </div>
-                <div className="flex w-1/2 flex-col gap-5">
+                    <select
+                      className={`w-full rounded-xl border bg-black px-4 py-3 text-sm text-white ${
+                        connectionStatuses[remoteSourceId] === 'online'
+                          ? 'border-emerald-700'
+                          : connectionStatuses[remoteSourceId] === 'offline'
+                            ? 'border-red-800'
+                            : 'border-slate-700'
+                      }`}
+                      value={remoteSourceId}
+                      onChange={(event) => {
+                        setRemoteSourceId(Number(event.target.value))
+                        setShowBrowser(false)
+                      }}
+                    >
+                      {connections.map((server) => {
+                        const st = connectionStatuses[server.id]
+                        const isOnline = st === 'online'
+                        const label = st === 'online' ? '● ' : st === 'offline' ? '● ' : st === 'checking' ? '◔ ' : '◦ '
+                        return (
+                          <option key={server.id} value={server.id} disabled={!isOnline}>
+                            {label}{server.name}{!isOnline ? (st === 'offline' ? ' (离线)' : ' (未知)') : ''}
+                          </option>
+                        )
+                      })}
+                    </select>
+                  </div>
+
+                  <div className="space-y-2">
+                    <div className="flex items-center justify-between">
+                      <span className="text-sm text-slate-300">源文件 / 文件夹路径</span>
+                      <button
+                        className={`flex items-center gap-1 rounded-lg px-2 py-1 text-xs transition ${
+                          showBrowser
+                            ? 'bg-purple-600 text-white'
+                            : 'border border-slate-700 text-slate-400 hover:border-purple-500 hover:text-purple-400'
+                        }`}
+                        onClick={() => setShowBrowser((v) => !v)}
+                      >
+                        <FolderOpen size={12} />
+                        {showBrowser ? '收起' : '浏览...'}
+                      </button>
+                    </div>
+                    <input
+                      className="w-full rounded-xl border border-slate-700 bg-black px-4 py-3 font-mono text-sm text-white"
+                      value={remoteSourcePath}
+                      onChange={(event) => setRemoteSourcePath(event.target.value)}
+                      placeholder="/opt/app"
+                    />
+                  </div>
+
+                  <div className="mt-auto rounded-xl border border-slate-800 bg-slate-950/50 px-4 py-3 text-xs text-slate-500">
+                    <p className="font-medium text-slate-400">📁 支持文件夹传输</p>
+                    <p className="mt-1">选择文件夹时，将在目标路径下创建同名子目录并递归传输所有内容。</p>
+                  </div>
+                </div>
+
+                {/* Target config */}
+                <div className="flex min-w-0 flex-1 flex-col gap-4 overflow-hidden">
                   <h3 className="flex items-center gap-2 text-sm font-bold text-blue-400">
                     <Target size={16} />
                     目标配置
                   </h3>
+
                   <label className="space-y-2">
                     <span className="text-sm text-slate-300">目标目录</span>
-                    <input className="w-full rounded-xl border border-slate-700 bg-black px-4 py-3 text-sm text-white" value={remoteTargetPath} onChange={(event) => setRemoteTargetPath(event.target.value)} />
+                    <input
+                      className="w-full rounded-xl border border-slate-700 bg-black px-4 py-3 text-sm text-white"
+                      value={remoteTargetPath}
+                      onChange={(event) => setRemoteTargetPath(event.target.value)}
+                    />
                   </label>
-                  <div className="flex-1 space-y-2">
-                    <div className="flex items-center justify-between">
+
+                  <div className="flex min-h-0 flex-1 flex-col space-y-2">
+                    <div className="flex shrink-0 items-center justify-between">
                       <span className="text-sm text-slate-300">目标服务器</span>
-                      <button className="text-xs text-blue-400" onClick={() => setTargetIds(connections.map((item) => item.id))}>
-                        全选
+                      <button
+                        className="text-xs text-blue-400"
+                        onClick={() => setTargetIds(connections.filter((c) => connectionStatuses[c.id] === 'online').map((c) => c.id))}
+                      >
+                        全选在线
                       </button>
                     </div>
-                    <div className="rounded-2xl border border-slate-700 bg-black p-2">
-                      {connections.map((server) => (
-                        <label key={server.id} className="flex items-center gap-2 rounded-xl px-3 py-2 hover:bg-slate-800">
+                    <div className="min-h-0 flex-1 overflow-y-auto rounded-2xl border border-slate-700 bg-black p-2">
+                      {connections.map((server) => {
+                        const st = connectionStatuses[server.id]
+                        const isOnline = st === 'online'
+                        return (
+                          <label
+                            key={server.id}
+                            className={`flex items-center gap-2 rounded-xl px-3 py-2 ${
+                              isOnline ? 'cursor-pointer hover:bg-slate-800' : 'cursor-not-allowed opacity-40'
+                            }`}
+                          >
                             <input
                               type="checkbox"
+                              disabled={!isOnline}
                               checked={targetIds.includes(server.id)}
                               onChange={() =>
                                 setTargetIds((prev) =>
@@ -268,20 +398,38 @@ export default function TransferCenterModal({
                                 )
                               }
                             />
+                            <StatusDot status={st} />
                             <span className="text-sm text-slate-300">{server.name}</span>
                           </label>
-                      ))}
+                        )
+                      })}
                     </div>
                   </div>
-                  <button className="flex w-full items-center justify-center gap-2 rounded-xl bg-purple-600 py-3 font-medium text-white transition hover:bg-purple-500" onClick={() => void handleStartRemote()}>
+
+                  <button
+                    className={`flex w-full items-center justify-center gap-2 rounded-xl py-3 font-medium transition ${
+                      !remoteSourceId || targetIds.length === 0 || !remoteSourcePath.trim()
+                        ? 'cursor-not-allowed bg-slate-800 text-slate-500'
+                        : 'bg-purple-600 text-white hover:bg-purple-500'
+                    }`}
+                    disabled={!remoteSourceId || targetIds.length === 0 || !remoteSourcePath.trim()}
+                    onClick={() => void handleStartRemote()}
+                  >
                     <Zap size={18} fill="currentColor" />
-                    跨服同步分发
+                    {!remoteSourceId
+                      ? '请选择源服务器'
+                      : !remoteSourcePath.trim()
+                        ? '请填写源路径'
+                        : targetIds.length === 0
+                          ? '请选择目标服务器'
+                          : '跨服同步分发'}
                   </button>
                 </div>
               </div>
             )}
           </div>
 
+          {/* Task status panel */}
           <div className="flex w-[360px] shrink-0 flex-col bg-[#0d1117]">
             <div className="flex items-center justify-between border-b border-slate-800 bg-slate-900 px-4 py-4">
               <h4 className="flex items-center gap-2 text-sm font-medium text-slate-200">
@@ -317,12 +465,8 @@ export default function TransferCenterModal({
                           </button>
                         ) : null}
                       </div>
-                      <div className="mb-1 flex justify-between text-xs text-slate-500">
-                        <span>{task.createdAt}</span>
-                        <span className={task.status === 'success' ? 'text-emerald-400' : 'text-blue-400'}>{task.progress}%</span>
-                      </div>
-                      <div className="h-1.5 rounded-full border border-slate-700 bg-slate-950">
-                        <div className={`h-1.5 rounded-full ${task.status === 'success' ? 'bg-emerald-500' : 'bg-blue-500'}`} style={{ width: `${task.progress}%` }} />
+                      <div className="text-xs text-slate-500">
+                        {task.createdAt}
                       </div>
                     </div>
                     <div className="max-h-48 space-y-1 overflow-auto bg-slate-900/60 p-2">
@@ -330,7 +474,10 @@ export default function TransferCenterModal({
                         <div key={item.id} className="rounded-xl p-2 hover:bg-slate-800">
                           <div className="flex justify-between text-xs">
                             <span className="truncate text-slate-300">{item.label}</span>
+                            <div className="flex items-center gap-2">
                               <span className="text-slate-500">{item.message}</span>
+                              <span className={item.status === 'success' ? 'text-emerald-400' : 'text-blue-400'}>{item.progress}%</span>
+                            </div>
                           </div>
                           <div className="mt-2 flex items-center gap-2">
                             <div className="h-1 flex-1 rounded-full bg-black">
@@ -356,5 +503,19 @@ export default function TransferCenterModal({
         </div>
       </div>
     </Modal>
+
+    {/* SFTP file selector popup — mounted outside the main modal so it overlays on top */}
+    {showBrowser && (
+      <SftpFileSelectorModal
+        open={showBrowser}
+        connection={connections.find((c) => c.id === remoteSourceId) ?? connections[0]}
+        onSelect={(path) => {
+          setRemoteSourcePath(path)
+          setShowBrowser(false)
+        }}
+        onClose={() => setShowBrowser(false)}
+      />
+    )}
+    </>
   )
 }

frontend/src/pages/WorkspacePage.tsx

@@ -757,8 +757,8 @@ export default function WorkspacePage({
                   'rounded-md p-2 transition',
                   layout === 'split' ? 'bg-slate-700 text-white' : 'text-slate-400 hover:text-white',
                 )}
-                onClick={() => setLayout('split')}
-                title="分屏"
+                onClick={() => setLayout(layout === 'split' ? 'terminal' : 'split')}
+                title={layout === 'split' ? '切换到终端' : '分屏'}
               >
                 <SplitSquareHorizontal size={15} />
               </button>
@@ -857,6 +857,7 @@ export default function WorkspacePage({
       <TransferCenterModal
         open={showTransferModal}
         connections={connections}
+        connectionStatuses={connectionStatuses}
         tasks={transferTasks}
         onTasksChange={setTransferTasks}
         onClose={() => setShowTransferModal(false)}