Electron AppImage: verify portable IPC handlers work on clean machine

[man4ish]

Goal

Confirm the portable Electron AppImage works without any pre-installed dependencies.

Steps

• Test AppImage on a clean Ubuntu 24.04 VM
• Verify all 12 IPC handlers respond correctly
• Confirm dynamic server IP configuration works via window.__OMNIBIOAI_SERVER__
• Test with server at 192.168.86.234 (DGX Spark)

Known issue

Full IPC handler implementation was completed in May 2026.
Verify nothing regressed.