Validated on the combined batch board over tip 0b41259f: static gates clean, typecheck:core clean, 430+ focused tests green across 5 groups.
--tray returns after readiness and survives terminal close, with tray-mode autostart on macOS/Windows/Linux while headless Linux keeps the systemd user service. tray-detached + autostart suites green. Closes#11229. Thank you @tuandinh0801!