Enable running dev cluster without the ceramic secret key

[m0ar]

Currently, the dev cluster needs to have the ceramic key set as an env secret to work correctly. This reduces setup burden internally, as the model IDs become deterministic. However, we can't share this key externally, currently blocking external devs to run the full stack.

The models need to be deployed from the desci-codex repo without assumptions on the key used, and the resulting model IDs need to be parsed and fed back into the cluster config somehow.