Weather Toolkit: Missing GDPS charts

**Describe the task**

Handle GDPS zero area polygons.

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

**Additional context**
- Add any other context about the task here.
- Or here

No file, test, or entry point is named in the issue; begin by locating the Weather Toolkit path that processes GDPS polygons and checking the existing chart-generation flow. Done means zero-area GDPS polygons are handled and the missing GDPS charts are available, with concrete acceptance checks replacing the placeholders.

Written by the indexing model from the issue text.