fix(cmd): use os.Kill on Windows since os.Interrupt is unsupported

Author: thejoeejoee

internal/cmd/sigwinch_windows.go

@@ -11,6 +11,7 @@ var sigWinch os.Signal // nil — no SIGWINCH on Windows; resize uses polling
 
 var errEIO = errors.New("input/output error")
 
-// terminateSignal is the signal sent to gracefully stop the child process.
-// On Windows os.Interrupt sends CTRL_BREAK_EVENT to the child.
-var terminateSignal os.Signal = os.Interrupt
+// terminateSignal is the signal used to stop the child process.
+// On Windows os.Interrupt is not supported by os.Process.Signal, so we use
+// os.Kill to terminate the process directly.
+var terminateSignal os.Signal = os.Kill