Fix: use absolute weights_dir in UAV_VisLoc script

Relative 'in/weights' path fails when script is run from outside the
project root. Use _PROJECT_ROOT / "in" / "weights" instead.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/run_uav_visloc.py

@@ -78,7 +78,7 @@ def main() -> None:
         "sand and gravel ground", "rocky terrain", "farmland",
         "railway", "parking lot", "sidewalk",
     ])
-    models_conf = ModelsConfig()
+    models_conf = ModelsConfig(weights_dir=str(_PROJECT_ROOT / "in" / "weights"))
 
     setup_logging(
         pipeline_conf.log_level,