[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/performance-tests.md

@@ -0,0 +1,43 @@
+# Performance Test Scenarios
+
+## PT-01: Single Tile Download Latency
+
+**Trigger**: GET /api/satellite/tiles/latlon (uncached tile)
+**Load**: 1 request
+**Expected**: Response within 30s (includes Google Maps round-trip)
+**Pass criterion**: Response time < 30000ms; HTTP 200
+
+## PT-02: Cached Tile Retrieval Latency
+
+**Trigger**: GET /api/satellite/tiles/latlon (cached tile)
+**Load**: 1 request
+**Expected**: Response within 500ms (DB lookup + response)
+**Pass criterion**: Response time < 500ms; HTTP 200
+
+## PT-03: Region Processing Throughput (200m)
+
+**Trigger**: POST /api/satellite/request with 200m region
+**Load**: 1 region
+**Expected**: Complete processing within 60s
+**Pass criterion**: status="completed" within 60s; tiles downloaded > 0
+
+## PT-04: Region Processing Throughput (500m with stitch)
+
+**Trigger**: POST /api/satellite/request with 500m region + stitch
+**Load**: 1 region
+**Expected**: Complete processing within 120s (more tiles + stitching)
+**Pass criterion**: status="completed" within 120s; stitched image exists
+
+## PT-05: Concurrent Region Requests
+
+**Trigger**: 5 simultaneous POST /api/satellite/request (different coordinates)
+**Load**: 5 concurrent requests
+**Expected**: All queued immediately; all complete within 5 minutes
+**Pass criterion**: All 5 regions reach status="completed"; queue does not reject
+
+## PT-06: Route Point Interpolation Speed
+
+**Trigger**: POST /api/satellite/route with 20 points
+**Load**: 1 request
+**Expected**: Route created (with interpolation) within 5s
+**Pass criterion**: HTTP 200 response within 5000ms; totalPoints > 20