T6 Map Page Improvements: geolocation fallback, location coordinates, friendly error messages

- Improved geolocation error messages (maps error codes to friendly text: Location blocked, GPS unavailable, GPS timed out)
- Added location data to list_assets API (location_latitude, longitude, address, building_name, building_number, name) via LEFT JOIN
- Map pins now use location coordinates as direct fallback when asset lacks own lat/lng
- GeocodeAndPin now falls back to location address fields when asset address is empty
- All 96 map-related tests pass (66 API + 30 frontend)

server.py

@@ -958,16 +958,30 @@ def list_assets(
     if assigned_to is not None:
         conditions.append("assigned_to = ?")
         params.append(assigned_to)
+    # Build conditions with table prefix for JOIN safety
     if q:
-        conditions.append("(name LIKE ? OR machine_id LIKE ? OR description LIKE ?)")
+        conditions.append("(a.name LIKE ? OR a.machine_id LIKE ? OR a.description LIKE ?)")
         like = f"%{q}%"
         params.extend([like, like, like])
 
-    where = " AND ".join(conditions)
-    sql = "SELECT * FROM assets"
+    where = " AND ".join(
+        f"a.{c}" if not c.startswith("(") else c
+        for c in conditions
+    ) if conditions else ""
+    sql = (
+        "SELECT a.*,"
+        " l.latitude AS location_latitude,"
+        " l.longitude AS location_longitude,"
+        " l.address AS location_address,"
+        " l.building_name AS location_building_name,"
+        " l.building_number AS location_building_number,"
+        " l.name AS location_name"
+        " FROM assets a"
+        " LEFT JOIN locations l ON a.location_id = l.id"
+    )
     if where:
         sql += f" WHERE {where}"
-    sql += " ORDER BY created_at DESC LIMIT ? OFFSET ?"
+    sql += " ORDER BY a.created_at DESC LIMIT ? OFFSET ?"
     params.extend([limit, offset])
 
     rows = conn.execute(sql, params).fetchall()