gershwin-on-freebsd: livecd rework + launchd port plan

Two-phase integration of freebsd-launchd work into gershwin-on-freebsd:
livecd hardening first (feat/libs-corebase branch flag, /boot/firmware
symlink, init_script cleanup, CI boot-test), then launchd as PID 1
(Option D pivot, rc.d-to-LaunchDaemon conversion table, gershwin-shaped
loginwindow plist). Phase 3 polish (kmodloader, configd, ASL) deferred.

Honors gershwin's existing resources/packages/* as settled work — only
adds dhcpcd and wpa_supplicant from ports for the launchd phase. No new
kmods. gershwin-developer at feat/libs-corebase is canonical for the
GNUstep+desktop install; freebsd-launchd lands at /Developer/Library/
Sources/freebsd-launchd/ per gershwin convention.

Phase 1 reviewed and approved; Phases 2–3 pending review after Phase 1
lands.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: pkgdemon