* 🗨️ fix: Safe Validation for Prompt Updates
- Added `safeValidatePromptGroupUpdate` function to validate and sanitize prompt group update requests, ensuring only allowed fields are processed and sensitive fields are stripped.
- Updated the `patchPromptGroup` route to utilize the new validation function, returning appropriate error messages for invalid requests.
- Introduced comprehensive tests for the validation logic, covering various scenarios including allowed and disallowed fields, enhancing overall request integrity and security.
- Created a new schema file for prompt group updates, defining validation rules and types for better maintainability.
* 🔒 feat: Add JSON parse error handling middleware
