- Removed `last_request` field and related logic for storing raw request string
- Replaced `_extract_output` and `_extract_extra_fields` to use `process_data` instead of `request`
- Updated `_build_content` to directly parse JSON body without intermediate rendering step
- Modified `execute` to generate `process_data` from actual HTTP request object instead of manual string building
- Added `process_data` field to `HttpRequestNodeOutput` model for consistent debugging info