feat: 加固 Agent CLI 执行边界并更新模型目录

收紧 SSH 命令护栏、权限校验与远程执行会话，并同步主流大模型供应商列表。

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/pkg/remoteexec/persistent_client.go

@@ -29,13 +29,21 @@ func NewPersistentClient(cfg SSHConfig) (*PersistentClient, error) {
 
 // Exec 在长连接上执行命令；连接断开时自动重连一次 // Logan.Li
 func (p *PersistentClient) Exec(command string, timeout time.Duration) (*ExecResult, error) {
+	return p.ExecContext(context.Background(), command, timeout)
+}
+
+// ExecContext 在长连接上执行命令，并在调用方取消时关闭当前远端 session。 // Logan.Li
+func (p *PersistentClient) ExecContext(ctx context.Context, command string, timeout time.Duration) (*ExecResult, error) {
 	p.mu.Lock()
 	defer p.mu.Unlock()
 
-	result, err := p.execLocked(command, timeout)
+	result, err := p.execLockedContext(ctx, command, timeout)
 	if err == nil {
 		return result, nil
 	}
+	if ctx.Err() != nil {
+		return result, ctx.Err()
+	}
 	// 连接级失败：重连后重试一次 // Logan.Li
 	if p.client != nil {
 		_ = p.client.Close()
@@ -46,11 +54,16 @@ func (p *PersistentClient) Exec(command string, timeout time.Duration) (*ExecRes
 		return result, err
 	}
 	p.client = client
-	return p.execLocked(command, timeout)
+	return p.execLockedContext(ctx, command, timeout)
 }
 
 // execLocked 假定已持锁，在当前 client 上执行 // Logan.Li
 func (p *PersistentClient) execLocked(command string, timeout time.Duration) (*ExecResult, error) {
+	return p.execLockedContext(context.Background(), command, timeout)
+}
+
+// execLockedContext 假定已持锁，并将调用方上下文传递给当前 SSH session。 // Logan.Li
+func (p *PersistentClient) execLockedContext(ctx context.Context, command string, timeout time.Duration) (*ExecResult, error) {
 	if p.client == nil {
 		client, err := connect(p.cfg)
 		if err != nil {
@@ -58,7 +71,7 @@ func (p *PersistentClient) execLocked(command string, timeout time.Duration) (*E
 		}
 		p.client = client
 	}
-	return execWithClient(p.client, p.cfg, command, timeout)
+	return execWithClientContext(ctx, p.client, p.cfg, command, timeout)
 }
 
 // Close 关闭长连接 // Logan.Li
@@ -75,6 +88,11 @@ func (p *PersistentClient) Close() error {
 
 // execWithClient 在已有 SSH client 上执行命令（供 Exec / PersistentClient 共用） // Logan.Li
 func execWithClient(client *ssh.Client, cfg SSHConfig, command string, timeout time.Duration) (*ExecResult, error) {
+	return execWithClientContext(context.Background(), client, cfg, command, timeout)
+}
+
+// execWithClientContext 在已有 SSH client 上执行命令，并响应调用方取消。 // Logan.Li
+func execWithClientContext(parent context.Context, client *ssh.Client, cfg SSHConfig, command string, timeout time.Duration) (*ExecResult, error) {
 	start := time.Now()
 	result := &ExecResult{Host: cfg.Host, Port: cfg.Port}
 
@@ -90,7 +108,7 @@ func execWithClient(client *ssh.Client, cfg SSHConfig, command string, timeout t
 		timeout = 60 * time.Second
 	}
 
-	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	ctx, cancel := context.WithTimeout(parent, timeout)
 	defer cancel()
 
 	type execOut struct {
@@ -117,10 +135,16 @@ func execWithClient(client *ssh.Client, cfg SSHConfig, command string, timeout t
 
 	select {
 	case <-ctx.Done():
+		_ = session.Signal(ssh.SIGKILL)
+		_ = session.Close()
 		result.Duration = time.Since(start).Milliseconds()
-		result.Error = fmt.Sprintf("执行超时（%v）", timeout)
+		if parent.Err() != nil {
+			result.Error = "执行已取消"
+		} else {
+			result.Error = fmt.Sprintf("执行超时（%v）", timeout)
+		}
 		result.ExitCode = -1
-		return result, fmt.Errorf("exec timeout after %v", timeout)
+		return result, ctx.Err()
 	case out := <-ch:
 		result.Duration = time.Since(start).Milliseconds()
 		result.Output = string(out.output)
@@ -141,4 +165,4 @@ func execWithClient(client *ssh.Client, cfg SSHConfig, command string, timeout t
 		}
 	}
 	return result, nil
-}
+}