fix(terminal): correct terminal message sending logic

Update the terminal message sending logic to use `sendString` with `false` instead of `writePlainMessage`. This ensures proper handling of terminal input without unnecessary revalidation and repainting.

Author: phodal

exts/ext-terminal/src/main/kotlin/cc/unitmesh/terminal/sketch/TerminalSketchProvider.kt

@@ -174,10 +174,7 @@ class TerminalSketchProvider : LanguageSketchProvider {
                 titleLabel.text = "Terminal - ($content)"
 
                 ApplicationManager.getApplication().invokeLater {
-//                    terminalWidget!!.terminalStarter?.sendString(content, true)
-                    terminalWidget!!.writePlainMessage(content)
-                    terminalWidget!!.revalidate()
-                    terminalWidget!!.repaint()
+                    terminalWidget!!.terminalStarter?.sendString(content, false)
                 }
 
                 isAlreadySent = true