[AZ-284] Autodev baseline + testability refactor

Phase A baseline outputs from /autodev (Steps 1-5):
- Problem & solution docs (_docs/00_problem, _docs/01_solution)
- Codebase documentation (_docs/02_document) incl. architecture,
  module-layout, glossary, system-flows, baseline compliance scan
- Test specs (blackbox, performance, resilience, security, resource,
  traceability matrix)
- Test task decomposition (_docs/02_tasks/todo): AZ-285..AZ-290
- Testability refactor (_docs/04_refactoring/01-testability-refactoring):
  - TC-01 Move DownloadedTileInfoV2 + new ExistingTileInfo to Common.DTO
  - TC-02 Replace dead ISatelliteDownloader API with real signatures
  - TC-03 GoogleMapsDownloaderV2 implements ISatelliteDownloader
  - TC-04 TileService depends on ISatelliteDownloader (mockable)
  - TC-05 DI + endpoints use ISatelliteDownloader
- Test runner scripts (scripts/run-tests.sh, run-performance-tests.sh)
- Autodev state pointer (_docs/_autodev_state.md)

Prepares the codebase for AZ-285..AZ-290 unit/integration test work.

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

_docs/02_tasks/todo/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