Navigation Mode Crash Fix

[Halcyonic-01]

Fixes #1373

1. Fixed Configuration Initialization (invesalius/session.py)

Corrected a typo that caused the app to falsely believe a project was still open from a previous session.

- self.project_status = 3
+ self._config["project_status"] = 3

2. Added Safety Guard (invesalius/control.py)

Added an early-return check in LoadProject() to prevent crashes when triggered without valid project data.

+ if not proj.threshold_range or not hasattr(proj, 'matrix_shape'):
+     if end_busy_cursor:
+         Publisher.sendMessage("End busy cursor")
+     return