fix exec cwd and env propagation

internal/api/handlers_exec.go

@@ -142,6 +142,8 @@ func (h *execHandler) Exec(w http.ResponseWriter, r *http.Request) {
 		Cmd:        req.Cmd,
 		Args:       req.Args,
 		TimeoutSec: req.TimeoutSec,
+		Envs:       req.Envs,
+		Cwd:        req.Cwd,
 	}))
 	if err != nil {
 		status, code, msg := agentErrToHTTP(err)

internal/api/handlers_exec_stream.go

@@ -35,9 +35,11 @@ var upgrader = websocket.Upgrader{
 
 // wsStartMsg is the first message the client sends to start a process.
 type wsStartMsg struct {
-	Type string   `json:"type"` // "start"
-	Cmd  string   `json:"cmd"`
-	Args []string `json:"args"`
+	Type string            `json:"type"` // "start"
+	Cmd  string            `json:"cmd"`
+	Args []string          `json:"args"`
+	Envs map[string]string `json:"envs"`
+	Cwd  string            `json:"cwd"`
 }
 
 // wsOutMsg is sent by the server for process events.
@@ -133,6 +135,8 @@ func (h *execStreamHandler) runExecStream(ctx context.Context, conn *websocket.C
 		SandboxId: sandboxIDStr,
 		Cmd:       startMsg.Cmd,
 		Args:      startMsg.Args,
+		Envs:      startMsg.Envs,
+		Cwd:       startMsg.Cwd,
 	}))
 	if err != nil {
 		sendWSError(conn, "failed to start exec stream: "+err.Error())