[AZ-373] Refactor C20: drop MapsVersion from new writes (option a)

- Stop writing "downloaded_YYYY-MM-DD" into tiles.maps_version: new rows
  bind @MapsVersion to NULL via TileService.BuildTileEntity.
- Retain the tiles.maps_version column (coderule.mdc forbids unprompted
  column drops); pre-existing rows keep their values for forensics.
- Remove MapsVersion property from DownloadTileResponse (API wire shape)
  and TileMetadata (internal DTO); OpenAPI schema regenerates from the
  DTO via Swashbuckle.
- Add 3 AC tests in TileServiceTests covering the captured-entity write
  (AC-1) and the DTO/wire-shape removal (AC-2).
- Update integration-test local DTO + console output; refresh docs in
  common_dtos.md, services_tile_service.md, data_model.md.
- Archive AZ-373 task file: todo/ -> done/.

174 unit + 5 smoke pass.

Co-authored-by: Cursor <cursoragent@cursor.com>

SatelliteProvider.Api/Program.cs

@@ -179,7 +179,6 @@ async Task<IResult> GetTileByLatLon([FromQuery] double Latitude, [FromQuery] dou
         TileSizeMeters = tile.TileSizeMeters,
         TileSizePixels = tile.TileSizePixels,
         ImageType = tile.ImageType,
-        MapsVersion = tile.MapsVersion,
         Version = tile.Version,
         FilePath = tile.FilePath,
         CreatedAt = tile.CreatedAt,