The registry rejected the v0.2.0 publish with a 422: it reads
packages[0].registryType, and server.json still used the 2025-07-09
snake_case spelling (registry_type, runtime_hint, runtime_arguments,
environment_variables, is_required, is_secret). Package sets
additionalProperties: false, so every key had to move to camelCase.
Validated locally against the 2025-09-29 schema.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>