SFMS: Data Service backend of snow mapping

**As a** User Type/Persona

**I need** Feature/enhancement

**So That** Value, why is this needed, what does the user need to accomplish

**Acceptance Criteria**
- [x] Creating PMTiles layer for consumption in our applications
- [x] create raster geo tiff in … spatial ref for other people to use
- [x] Can choose multi spatial ref (stick with standard proj for prov?), or lambert conformal (LCC)
- [ ] How do we want to share? DL from S3, User specify end point direct file download

**Additional Context**
- enter text here
- enter text here

**Definition of Done**
https://github.com/bcgov/wps/wiki/Definition-of-Done

No files, tests, or entry points are named in the issue. First clarify the sharing approach for the PMTiles and raster GeoTIFF outputs, then inspect the existing SFMS data-service backend; the work is done when the agreed download or endpoint-sharing flow is implemented and documented.

Written by the indexing model from the issue text.