[Feature Request] Add project subagents support to desktop application

Bug Description
Bring project subagents to the desktop app.

Environment Info

• Platform: darwin
• Terminal: Apple_Terminal
• Version: 2.1.109
• Feedback ID: a63df2cc-5ec8-47ca-8dce-b7de70ae1dcc

Errors

[{"error":"RangeError [ERR_CHILD_PROCESS_STDIO_MAXBUFFER]: stdout maxBuffer length exceeded\n    at Socket.onChildStdout (node:child_process:484:14)\n    at Socket.emit (node:events:508:28)\n    at addChunk (node:internal/streams/readable:559:12)\n    at readableAddChunkPushByteMode (node:internal/streams/readable:510:3)\n    at Readable.push (node:internal/streams/readable:390:5)\n    at Pipe.onStreamRead (node:internal/stream_base_commons:189:23)","timestamp":"2026-04-15T21:54:17.255Z"}]