## What changed
Raise the per-entry limit for plugin `interface.defaultPrompt` from 128 to 512 characters, retaining the maximum of three prompts. Update the protocol documentation and generated schemas and bindings to reflect the new limit.
## Testing
Update manifest coverage to accept a 512-character Unicode prompt and reject an over-limit prompt. Adjust the discovery warning test to use a 513-character prompt.
GitOrigin-RevId: 0ba3ceb253edf22a583f774492934b7c9b5ac231