- fetch_recipe_from_repos() iterates repos by priority, channels, with
mirror fallback — caches indexes at /cache/indexes/
- Conditional HTTP downloads (curl -z) to only re-fetch stale indexes
- build_registry and fetch-package prefer repos { } over remotes = [...]
when both are present
- Fallback chain: local .kap → repos (index-aware) → remotes (legacy)