Ego currently sync both the meta-repo and kits from the same sync uri.

In many instances, including cross-dev, shared containers, prefix, or dev usage, it is desirable to allow the meta_repo to be synced from one source (possibly local), while syncing the individual kits from another (possibly shared) source.

In addition to

config.sync_base_url

which should be the default, fallback value for the following, add

config.meta_repo_sync_base_url

config.kits_sync_base_url