Refactor golden image handling in backup upload process</message>

<message>Update the _set_golden_from_path function to improve the handling of existing golden image files. Replace the existing unlink logic with a more robust method that safely removes files or broken symlinks using the missing_ok parameter. This change enhances the reliability of the backup upload process by ensuring that stale references are properly cleared before setting a new golden image path.

backup-from-device/gnss-guard/tm-gnss-guard/utils/distance.py

@@ -0,0 +1,59 @@
+#!/usr/bin/env python3
+"""
+Distance calculation utilities using Haversine formula
+"""
+
+import math
+from typing import Optional
+
+
+def haversine_distance(
+    lat1: float, lon1: float, lat2: float, lon2: float
+) -> Optional[float]:
+    """
+    Calculate the great circle distance between two points on Earth using Haversine formula.
+    
+    Args:
+        lat1: Latitude of first point in degrees
+        lon1: Longitude of first point in degrees
+        lat2: Latitude of second point in degrees
+        lon2: Longitude of second point in degrees
+    
+    Returns:
+        Distance in meters, or None if calculation fails
+    """
+    try:
+        # Validate inputs
+        if not all(isinstance(x, (int, float)) for x in [lat1, lon1, lat2, lon2]):
+            return None
+        
+        # Check if coordinates are valid
+        if not (-90 <= lat1 <= 90) or not (-90 <= lat2 <= 90):
+            return None
+        if not (-180 <= lon1 <= 180) or not (-180 <= lon2 <= 180):
+            return None
+
+        # Earth's radius in meters
+        R = 6371000
+
+        # Convert degrees to radians
+        phi1 = math.radians(lat1)
+        phi2 = math.radians(lat2)
+        delta_phi = math.radians(lat2 - lat1)
+        delta_lambda = math.radians(lon2 - lon1)
+
+        # Haversine formula
+        a = (
+            math.sin(delta_phi / 2) ** 2
+            + math.cos(phi1) * math.cos(phi2) * math.sin(delta_lambda / 2) ** 2
+        )
+        c = 2 * math.atan2(math.sqrt(a), math.sqrt(1 - a))
+
+        # Distance in meters
+        distance = R * c
+
+        return distance
+
+    except (ValueError, TypeError, OverflowError):
+        return None
+