fix: handle xterm selection disposable cleanup

Author: pallyoung

packages/web/src/features/terminal-panel/__tests__/xterm-host.test.tsx

@@ -244,6 +244,20 @@ describe("XtermHost", () => {
     expect(consoleSpy).toHaveBeenCalledWith("Failed to dispose xterm instance:", expect.any(Error));
   });
 
+  it("does not crash on unmount when onSelectionChange returns a disposable object", () => {
+    mockTerminal.onSelectionChange.mockImplementationOnce(() => ({
+      dispose: vi.fn(),
+    }));
+
+    const { unmount } = render(
+      <JotaiProvider>
+        <XtermHost terminalId="selection-disposable-terminal" workspaceId="test-workspace" />
+      </JotaiProvider>
+    );
+
+    expect(() => unmount()).not.toThrow();
+  });
+
   it("renders without crashing", () => {
     const { container } = render(
       <JotaiProvider>

packages/web/src/features/terminal-panel/views/shared/xterm-host.tsx

@@ -1115,7 +1115,7 @@ export function XtermHost({
     terminal.onData((data) => {
       void handleInputRef.current(data);
     });
-    const disposeSelectionChange =
+    const selectionChangeDisposable =
       typeof terminal.onSelectionChange === "function"
         ? terminal.onSelectionChange(() => {
             selectedTextRef.current = terminal.hasSelection() ? terminal.getSelection() : "";
@@ -1778,7 +1778,11 @@ export function XtermHost({
         terminalRef.current = null;
         fitAddonRef.current = null;
       }
-      disposeSelectionChange?.();
+      if (typeof selectionChangeDisposable === "function") {
+        selectionChangeDisposable();
+      } else {
+        selectionChangeDisposable?.dispose?.();
+      }
     };
   }, [
     dispatch,