[FEATURE] Embed DuckDB SQL macros in STAC catalog metadata

[jjcfrancisco]

Background

Querying Overture via DuckDB requires knowing the exact S3 release path.
labs.overturemaps.org/data/latest.ddb solves this with pre-built views,
but it's a separate artifact that must be regenerated each release.

Proposal

Add a duckdb field to the STAC catalog JSON with SQL that creates one view
per type pointing at the correct S3 paths:

curl https://stac.overturemaps.org/catalog.json | jq -r .duckdb | duckdb overture.db -c -
# then: SELECT * FROM place;