Re-factor model processing

**Describe the task**
In retrospect, storing the 4 points around a station is a bad idea. (or at least, if it's going to be stored, it should be stored somewhere else).
The process for downloading and interpolating/machine learning should be adjusted to just go directly into a processed table.

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

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

No files, tests, or entry points are identified in the issue, so begin by locating the download, interpolation, machine-learning, and model-processing code. Clarify the processed-table design and define completion as removing the four-point station storage while preserving direct processing into the table and verifying the full workflow.

Written by the indexing model from the issue text.