refactor: Use DRY approach for $parameters schema with $ref

- Add ParametersProp definition in definitions section
- Replace 71 inline $parameters blocks with $ref to ParametersProp
- Run poe build to regenerate Pydantic models
- This makes the schema more maintainable by defining the $parameters description once

Co-Authored-By: AJ Steers <[email protected]>

Author: devin-ai-integration[bot]