PyPortal_Hurricane_Tracker code can fail if movementDir JSON API call returns None

PyPortal_Hurricane_Tracker code.py
**TypeError: can't convert NoneType to float line 136**

Caused by movementDir JSON being None if the hurricane has not moved.

This will skip the direction arrow but keep all the other graphics:
```
# add direction arrow
movement_dir = storm.get("### movementDir")
if movement_dir is not None:
angle = math.radians(float(movement_dir))
xd = x + int(ARROW_LENGTH * math.sin(angle))
yd = y - int(ARROW_LENGTH * math.cos(angle))
arrow = Line(x, y, xd, yd, color=ARROW_COLOR)
storm_gfx.append(arrow)
# add the storm graphics
storm_icons.append(storm_gfx)
```

Open PyPortal_Hurricane_Tracker code.py and inspect the movementDir handling around line 136. Check the JSON value before converting it to a float, then run the tracker to confirm that a missing direction skips only the direction arrow while preserving the other storm graphics.

Written by the indexing model from the issue text.