The right-hand panel gains a "RIO port" row under Triggers: an editable
combo offering the app default (shown with its value), the machine's COM
ports, and pipe:vrio, with free text for anything else. Save stores the
endpoint in RioProfile.RioComPort (blank or the default entry = null =
follow DefaultRioComPort).
Because the editor session holds the endpoint it opened with, a saved
port change now re-arms the session live: the tray host unhooks the old
runtime's editor wiring, re-activates on the new endpoint, re-hooks, and
restores the output-gate state - so the live RIO commands and button
echo follow the new port/pipe without closing the editor.
Verified with the offline DrawToBitmap harness (layout, both default and
pipe:vrio states) plus a scripted save round-trip (default->null,
pipe:vrio->stored, blank->null, reopen shows stored COM7).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>