Laptop run (YuKu, existing machine) exposed two fresh-install blind
spots:
1. Terra add failed on a machine that already HAD the repo but not a
queryable terra-release RPM — bootstrapping --repofrompath over an
existing repo id collides. New repo_enabled() checks dnf repolist
(the source of truth); add_terra_repo and add_rpmfusion_repo now
skip when the repo is configured OR the release RPM present.
2. PeaZip tailoring tried gtk3 over an existing peazip-qt5: all UI
flavors ship /usr/bin/peazip and file-conflict, transaction died.
Any installed flavor (qt5/qt6/gtk3/gtk2) now wins and the section
skips with the flavor named.
Harness: laptop sim (repo configured, peazip-qt5 present) -> zero
bootstrap calls, PeaZip skipped; fresh machine -> terra bootstraps +
gtk3 installs; re-run -> skip via repolist; peazip-qt6 + hyprland ->
skip; unattended/piped green.
Pathfinder
b79735d82e