Add stac-table-columns renderer to overture-schema-codegen

Type

Task

Scope

Multi-theme or Platform

Skillset

engineering

Description

Context

The STAC catalog at stac.overturemaps.org emits table:columns with only column names — no type or description. Consumers reading the catalog have no way to discover what a column means without leaving STAC and going to the schema docs. The information already lives in the Pydantic models; a new codegen renderer can surface it as machine-readable JSON that the STAC generator consumes at build time.

Proposed change

In packages/overture-schema-codegen/src/overture/schema/codegen/, alongside markdown/ and pyspark/:

• Add a stac_table_columns/ renderer that emits one JSON file per (theme, type), matching the STAC table extension table:columns shape: [{"name", "type", "description"}].
• type maps from the Pydantic field's resolved primitive to STAC/parquet types (string, int32, int64, double, boolean, struct, list). Reuse extraction logic already used by the pyspark renderer where possible.
• description comes from the field's docstring / description text.
• Wire into the CLI as a new --format option so overture-codegen generate --format stac-table-columns --output-dir out/ writes buildings/building.json, places/place.json, etc.