fix(terminal): refactor WS cleanup, improve clear detection, fix sendToTerminal

- Move defer cleanup after async goroutine setup to prevent premature closure
- Remove unused Password field from terminal sessions struct
- Fix line calculation in clear detection using viewportY instead of baseY
- Add onStateChange callback to connectWebSocket for connection state
- Add tabId parameter to sendToTerminal for targeted tab control
- Simplify ShellAIMessage to use specific tab for command sending

💘 Generated with Crush

Assisted-by: MiniMax-M2.7 via Crush <crush@charm.land>

internal/api/terminal.go

@@ -146,13 +146,6 @@ func (s *Server) handleTerminalWS(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	log.Printf("terminal: pty started successfully")
-	defer func() {
-		ptmx.Close()
-		if cmd.Process != nil {
-			cmd.Process.Kill()
-			cmd.Wait()
-		}
-	}()
 
 	var once sync.Once
 	cleanup := func() {
@@ -164,6 +157,7 @@ func (s *Server) handleTerminalWS(w http.ResponseWriter, r *http.Request) {
 			}
 		})
 	}
+	defer cleanup()
 
 	go func() {
 		buf := make([]byte, 4096)
@@ -230,12 +224,11 @@ func (s *Server) handleTerminalSessions(w http.ResponseWriter, r *http.Request)
 		return
 	}
 	var body struct {
-		Name     string `json:"name"`
-		Host     string `json:"host"`
-		Port     int    `json:"port"`
-		User     string `json:"user"`
-		Password string `json:"password"`
-		KeyPath  string `json:"key_path"`
+		Name    string `json:"name"`
+		Host    string `json:"host"`
+		Port    int    `json:"port"`
+		User    string `json:"user"`
+		KeyPath string `json:"key_path"`
 	}
 	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
 		writeError(w, err.Error(), http.StatusBadRequest)