…gistry

Adds a new `astro api registry` command that provides access to the public
Airflow Provider Registry (https://airflow.apache.org/registry), following
the same patterns as `astro api airflow` and `astro api cloud`.

Supports both path-based and operation ID-based queries:
  astro api registry /providers.json
  astro api registry getProviderModulesLatest -p providerId=amazon
  astro api registry getProviderModulesByVersion -p providerId=amazon -p version=9.22.0
  astro api registry ls
  astro api registry describe getProviderModulesLatest

Uses the same base flags and infrastructure as airflow/cloud: -X, -F, -f,
-H, -p, -i, -q, -t, --silent, --verbose, --generate.

Reuses the shared RequestOptions, executeRequest, resolveOperationID,
applyPathParams, and openapi.Cache infrastructure. No new dependencies.