AZ-357 — eliminate year-based tile cache expiry (LF-1):
- Migration 012: drop 5-col unique index, dedupe by (lat,lon,zoom,
size) keeping max(updated_at), add new 4-col unique index, make
version column nullable + drop default. Column itself preserved
per coderule (column drops require explicit confirmation; tracked
in AZ-373 / C20).
- TileEntity.Version, TileMetadata.Version, DownloadTileResponse.
Version: int -> int? (HTTP shape preserved; field still in JSON).
- TileService.DownloadAndStoreTilesAsync: drop currentVersion year
computation and the .Where(t => t.Version == currentVersion)
cache filter. BuildTileEntity: drop year arg; write Version=null.
- TileRepository: ON CONFLICT now 4-col; lookup queries
ORDER BY updated_at DESC instead of version DESC.
- Tests: replace inverted BT02b with positive AZ357_AC1
(prior-year cached tile is reused). Add BuildTileEntity_
DoesNotPopulateVersion_AZ357 to enforce the no-write contract.
- 69 unit + 5 smoke + 3 stub-contract integration tests pass.
Cumulative code review (batches 7-9, 7 tasks): VERDICT=PASS.
Report at _docs/03_implementation/reviews/batch_09_review.md.
Zero Critical/High/Medium/Low findings. Architecture baseline
remains clean.
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>