[AZ-286] [AZ-287] [AZ-288] Service-level unit tests (mocked deps)

Batch 2: 27 new tests, 31/31 total passing.

AZ-286 TileService (9 tests):
- BT-01 download stores tiles via repository
- BT-02 cache reuse passes existing tiles to downloader
- BT-02b stale-version cached tiles are NOT treated as still-valid
- BT-N02 GoogleMapsDownloaderV2 rejects zoom levels not in {15..19}
- GetTileAsync known/unknown id

AZ-287 RegionService (6 tests):
- AC-1 RequestRegionAsync inserts entity and queues request
- AC-2/AC-3 ProcessRegionAsync transitions queued→processing→completed
  and writes CSV + summary files
- AC-4 stitch path is set when stitchTiles=true
- ProcessRegionAsync handles RateLimitException by writing failed
  summary with the error message preserved
- GetRegionStatusAsync mapping
- Missing region id is logged and short-circuits without DB writes

AZ-288 RouteService (12 tests):
- AC-1 every consecutive pair is ≤200m apart on 2-point route
- AC-2 first/last user points keep their roles; middles are interpolated
- BT-10 10pt route → 1 start, 1 end, 8 action, plus intermediates
- BT-12 20pt route → 1 start, 1 end, 18 action
- AC-3 TotalDistanceMeters == Σ Haversine(point[i-1], point[i])
- BT-N03 < 2 points throws ArgumentException
- regionSize <100 / >10000 throws ArgumentException
- BT-N04 (0,0) corner throws
- BT-N05 inverted NW.lat <= SE.lat throws
- BT-11 valid geofence creates region requests + links them with
  isGeofence=true
- BT-07 GetRouteAsync returns route + points
- GetRouteAsync unknown id returns null

Code review: PASS_WITH_WARNINGS — 3 Low Spec-Gap findings:
  1. BT-N01 (invalid coords) deferred to AZ-289 integration tests
     (TileService doesn't validate coordinates — API-layer concern)
  2. Point-type label drift between blackbox-tests.md ("original")
     and code ("start"/"action"/"end")
  3. Region status drift: spec "pending" vs code "queued" — initial
     state on insert

Verification: docker dotnet test — 31/31 pass in 0.83s.
Co-authored-by: Cursor <cursoragent@cursor.com>

_docs/02_tasks/done/AZ-286_tile_service_tests.md

@@ -0,0 +1,30 @@
+# Unit Tests: TileService
+
+**Task**: AZ-286_tile_service_tests
+**Name**: Unit tests: TileService (download, cache, dedup)
+**Complexity**: 3 points
+**Dependencies**: AZ-285
+**Component**: Blackbox Tests
+**Tracker**: AZ-286
+**Epic**: AZ-284
+
+## Scenarios
+
+- BT-01: Tile download — mock ISatelliteDownloader.DownloadSingleTileAsync returns tile info; verify TileService stores it via ITileRepository.InsertAsync
+- BT-02: Cache reuse — mock ITileRepository.GetTilesByRegionAsync returns existing tile; verify ISatelliteDownloader receives existing tiles to skip
+- BT-N01: Invalid coordinates — verify appropriate error handling for out-of-range lat/lon
+- BT-N02: Invalid zoom level — verify GoogleMapsDownloaderV2 rejects zoom levels outside allowed range
+
+## Test Data
+
+Coordinates from `input_data/test_coordinates.md`: lat=47.461747, lon=37.647063, zoom=18
+
+## Expected Results
+
+Per `input_data/expected_results/results_report.md`: tile with zoomLevel=18, tileSizePixels=256, imageType="jpg", non-empty filePath
+
+## Acceptance Criteria
+
+AC-1: All 4 scenarios have passing tests
+AC-2: ISatelliteDownloader is mocked (no real Google Maps calls)
+AC-3: Tests verify both happy path and error paths