[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_document/tests/test-data.md

@@ -0,0 +1,30 @@
+# Test Data Management
+
+## Data Sources
+
+| Source | Location | Type |
+|--------|----------|------|
+| Test coordinates | `_docs/00_problem/input_data/test_coordinates.md` | Static reference data |
+| Expected results | `_docs/00_problem/input_data/expected_results/results_report.md` | Pass/fail criteria |
+| Generated tiles | ./tiles/ (Docker volume) | Runtime artifacts |
+| Output files | ./ready/ (Docker volume) | Runtime artifacts |
+
+## Test Data Lifecycle
+
+1. **Before test run**: Fresh PostgreSQL database (empty, migrations applied on API startup)
+2. **During test run**: Each test creates its own data (unique GUIDs for routes/regions)
+3. **After test run**: Data persists in volumes for inspection; DB data disposable
+
+## Data Isolation
+
+- Each test uses `Guid.NewGuid()` for region/route IDs — no conflicts between tests
+- Tests run sequentially — no concurrency conflicts
+- Tile cache is shared across tests (by design — tests tile reuse)
+
+## Reference Coordinates
+
+| Label | Latitude | Longitude | Use |
+|-------|----------|-----------|-----|
+| Tile/Region test point | 47.461747 | 37.647063 | Tile download, region processing |
+| Route area (start) | 48.276067 | 37.384458 | Route creation, map processing |
+| Route area (east) | 48.276067 | 37.519458 | Extended route (non-overlapping) |