Honor YOLO preflight environment config

backend/scripts/yolo_preflight.py

@@ -19,7 +19,7 @@ def main() -> int:
     parser.add_argument("--model-path", help="Existing local YOLO model path.")
     parser.add_argument("--tile-manifest-path", help="Existing raster tile manifest path.")
     parser.add_argument("--enabled", action="store_true", help="Treat YOLO as enabled for this preflight.")
-    parser.add_argument("--max-tiles", type=int, default=100, help="Maximum tile count allowed by preflight.")
+    parser.add_argument("--max-tiles", type=int, help="Maximum tile count allowed by preflight.")
     parser.add_argument(
         "--assume-dependencies",
         action="store_true",
@@ -35,11 +35,16 @@ def main() -> int:
     if args.check_model_load and args.assume_dependencies:
         parser.error("--check-model-load cannot be combined with --assume-dependencies")
 
-    settings = Settings(
-        yolo_enabled=args.enabled or bool(args.model_path),
-        yolo_model_path=args.model_path,
-        yolo_max_tiles=args.max_tiles,
-    )
+    settings = Settings()
+    settings_updates = {}
+    if args.enabled or args.model_path:
+        settings_updates["yolo_enabled"] = True
+    if args.model_path:
+        settings_updates["yolo_model_path"] = args.model_path
+    if args.max_tiles is not None:
+        settings_updates["yolo_max_tiles"] = args.max_tiles
+    if settings_updates:
+        settings = settings.model_copy(update=settings_updates)
     payload = YoloPreflightService.run(
         settings=settings,
         tile_manifest_path=args.tile_manifest_path,

backend/tests/test_sprint13_yolo_preflight.py

@@ -197,6 +197,36 @@ def test_yolo_preflight_script_outputs_json(tmp_path: Path) -> None:
     assert payload["tile_manifest_path"] == str(manifest_path)
 
 
+def test_yolo_preflight_script_uses_environment_configuration(tmp_path: Path, monkeypatch) -> None:
+    model_path = tmp_path / "model.pt"
+    model_path.write_bytes(b"weights")
+    manifest_path = _manifest(tmp_path)
+    monkeypatch.setenv("YOLO_ENABLED", "true")
+    monkeypatch.setenv("YOLO_MODEL_PATH", str(model_path))
+    monkeypatch.setenv("YOLO_MAX_TILES", "4")
+
+    result = subprocess.run(
+        [
+            sys.executable,
+            str(ROOT / "scripts" / "yolo_preflight.py"),
+            "--tile-manifest-path",
+            str(manifest_path),
+            "--assume-dependencies",
+            "--json",
+        ],
+        cwd=ROOT,
+        check=True,
+        capture_output=True,
+        text=True,
+    )
+    payload = json.loads(result.stdout)
+
+    assert payload["status"] == "ready"
+    assert payload["checks"]["enabled"] is True
+    assert payload["model_path"] == str(model_path)
+    assert payload["max_tiles"] == 4
+
+
 def test_yolo_preflight_script_rejects_assumed_dependencies_for_model_load(tmp_path: Path) -> None:
     result = subprocess.run(
         [