Mapping between the item JSON fields and the actual CQL2 queryable names

[kmanolarakis]

While integrating CQL2 filters, I noticed that several item fields (e.g. id, collections, etc.) work in STAC search but are not mapped as CQL2 queryables or are mapped with different names, so filtering via {"property": "…"}returns empty results.

For example id was actually mapped as in CQL2 as identifier

Could you please provide the mapping between the item JSON fields and the actual CQL2 queryable names that the backend supports (i.e., what /queryables exposes and how each one maps to the underlying database fields)?
This will help build correct CQL2 expressions and avoid unsupported properties.