fix: fall back to node-pty when Bun is not defined (Electron/Node.js) (#1446)

Co-authored-by: Letta Code <noreply@letta.com>

build.js

@@ -49,7 +49,7 @@ await Bun.build({
   // Keep most native Node.js modules external to avoid bundling issues
   // But don't make `sharp` external, causes issues with global Bun-based installs
   // ref: #745, #1200
-  external: ["ws", "@vscode/ripgrep"],
+  external: ["ws", "@vscode/ripgrep", "node-pty"],
   features: features,
 });