Cortex.cpp: Built-in model library format

[freelerobot]

Problem

• our current corteso branches, model variant aliases have become a clusterneuken and is unmaintainable
• lets define some basic rules for how we plan to handle built in models and their variants.

Questions

• How should we organize the repo?
• How do model variants map to respective branches?
• Model variants have a declarative long form q4_k_s_8b vs an alias 8b, how should we design this?
• Do we need a metadata.yaml or metadata.json in the main branch to indicate all supported variants? And also to include decorator attrs like license author tags?
• Should we remove all the remote model.yamls, like gpt/claude (seems like a bad previous decision)?
• How can we leverage HF's collections feature? https://huggingface.co/collections/cortexso/curated-models-6687ab2fbec843c68109bd51

cc @louis-jan @hiento09 @dan-homebrew @nguyenhoangthuan99