[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/security-tests.md

@@ -0,0 +1,25 @@
+# Security Test Scenarios
+
+## SEC-01: SQL Injection via Coordinate Parameters
+
+**Trigger**: GET /api/satellite/tiles/latlon?Latitude=1;DROP TABLE tiles--&Longitude=1&ZoomLevel=18
+**Expected**: Request rejected or treated as invalid parameter
+**Pass criterion**: HTTP 400 or parameter parsing error; no database damage; tiles table intact
+
+## SEC-02: Path Traversal in Tile Serving
+
+**Trigger**: GET /tiles/18/../../../etc/passwd
+**Expected**: Request rejected; no file outside tiles directory served
+**Pass criterion**: HTTP 404 or 400; response body does not contain system file content
+
+## SEC-03: Oversized Region Request
+
+**Trigger**: POST /api/satellite/request with sizeMeters=999999999
+**Expected**: Either rejected or handled without resource exhaustion
+**Pass criterion**: No OOM; no infinite processing; either error response or bounded processing
+
+## SEC-04: Malformed JSON in Route Request
+
+**Trigger**: POST /api/satellite/route with invalid JSON body
+**Expected**: Parse error returned
+**Pass criterion**: HTTP 400; error message indicates parsing failure; no crash