v0.1.2: Bump to 0.1.2, fix server.json for the live MCP Registry schema

The v0.1.1 release's "Publish server to MCP Registry" step failed:

  Error: publish failed: server returned status 422:
  {"errors":[{"message":"expected length >= 1",
  "location":"body.packages[0].registryType","value":""}]}

server.json was written against the schema dated 2025-07-09
(snake_case: registry_type, registry_base_url, runtime_hint,
is_required, is_secret, website_url), but the live registry API
(confirmed via its own openapi.yaml) now expects the 2025-12-11
schema's camelCase field names. The old keys were silently ignored as
unknown properties, so registryType came through empty and got
rejected by the length>=1 validation.

Renamed every field to match the live schema and bumped $schema to
2025-12-11. Also bumped to 0.1.2 since 0.1.1 already published
successfully to npm in the prior (partially fixed) run -- npm refuses
to republish an existing version, so this release needs a fresh one.