Address round-3 code-review note on PR #1587: resource `_meta` is applied
only by the default read handler; a customHandler from onRegisterResource
replaces the contents wholesale and would drop it. Document this on
ResourceDefinition._meta so a future App UI resource with a custom read
handler knows to re-add _meta itself.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S3fTN8H3R8YV4yUGvZjYnX