Weather Toolkit: RDPS set as default model

**Describe the task**

RDPS is the default model instead of GDPS

**Acceptance Criteria**
- [ ] first
- [ ] second
- [ ] third

**Additional context**
- SME = Liz
- Or here

Start by locating the Weather Toolkit configuration or entry point where GDPS is selected as the default model, then review the surrounding model-selection flow. Replace the default with RDPS and verify the three acceptance criteria, which should be clarified with SME Liz before implementation.

Written by the indexing model from the issue text.