Include Slope in Fire Behaviour Calculator (old) Table

**As a** *(User Type/Persona)* **I want** *(Feature/enhancement)* **So That** *(Value, why is this wanted, what is the user trying to accomplish)*

**Additional Context**
- not an MVP feature
- either a slope column or include it in variables such as windspeed
- need an SME for grooming

**Acceptance Criteria**
- [ ] Given (Context), When (action carried out), Then (expected outcome)
- [ ] Given (Context), When (action carried out), Then (expected outcome)

The issue names no files, tests, or entry points. First obtain SME guidance and define whether slope is a table column or part of another variable, then write concrete acceptance criteria; done means the old Fire Behaviour Calculator table represents slope as agreed.

Written by the indexing model from the issue text.