Hardening: DREAMCONNECT_HOST_ACCOUNT pointed at an existing account is now
fully reversible (H6) — a crash-safe one-host-account-per-box invariant,
root/user/local reserved everywhere without breaking classic-mode
autologin, and home-directory validation covering the account's own
hand-deleted-account scenario.
The account path itself still needs a full on-device reboot verification
(unchanged from v1.4).
See #21.