Replaces bare strings with two enums in Common/Enums/:
RegionStatus { Queued, Processing, Completed, Failed }
RoutePointType { Start, End, Action, Intermediate }
Adds a Dapper EnumStringTypeHandler<T> (DataAccess/TypeHandlers/)
that round-trips enums to/from lowercase strings, registered once
at startup via DapperEnumTypeHandlers.RegisterAll(). DataAccess now
references Common (project ref) so entities can carry the enum types.
Sites converted: RegionService (5), RouteProcessingService (3),
RoutePointGraphBuilder (4), entity Status/PointType columns. Log
message and summary file format preserved via .ToLowerInvariant().
API JSON contract preserved by adding JsonStringEnumConverter with
JsonNamingPolicy.CamelCase to the http JSON options — single-word
enum members serialize to the same lowercase strings as before.
DTO renamed: Common.DTO.RegionStatus -> RegionStatusResponse to
free the RegionStatus name for the new enum (forced by the task's
explicit enum name); the renamed DTO has no public-API impact at
the JSON wire level. Stale doc references updated.
AC RT2 in _docs/00_problem/acceptance_criteria.md now lists all 4
point types (start/end/action/intermediate).
Tests: 171 / 171 unit + 5 / 5 smoke green (was 141 + 5; +30 new tests
covering type handler round-trip, set/parse, unknown-value rejection,
idempotent registration, and the AC RT2 doc check).
Co-authored-by: Cursor <cursoragent@cursor.com>
Move cache+DB+download logic for /tiles/{z}/{x}/{y} and
/api/satellite/tiles/latlon out of Program.cs into TileService.
Endpoints now inject only ITileService + ILogger. Service owns
IMemoryCache (1h absolute / 30min sliding preserved). Added
TileBytes DTO; ITileService gains GetOrDownloadTileAsync and
DownloadAndStoreSingleTileAsync. 5 new unit tests cover cache
hit, repo hit, downloader fallback, and AZ-311 happy + error.
Build clean (0/0), unit suite 40/40. Resolves architecture
baseline F3 in code (docs handled by AZ-315).
Co-authored-by: Cursor <cursoragent@cursor.com>