- install.sh: use realpath to follow symlinks when deriving OMARCHY_PATH
from script location. Logical pwd left dev-link symlink chains pointing
at the wrong dir; realpath resolves to the underlying checkout.
- install/helpers/mode.sh: validate explicit OMARCHY_INSTALL_MODE values
and exit on typos. Also export_legacy_mode_flags now UNSETS the
contradictory legacy flag for each mode so unmigrated callers can't
see both OMARCHY_CHROOT_INSTALL=1 and OMARCHY_ONLINE_INSTALL=true.
- install/helpers/errors.sh: retry uses "$OMARCHY_PATH/install.sh"
and preserves OMARCHY_INSTALL_MODE explicitly; the previous hardcoded
~/.local/share/omarchy/install.sh broke package-mode retries.
- bin/omarchy-install-mode: soften the summary; the helper only knows
the current env, not any persisted post-install state.