Missing null/instance checks in `_on_collided`

[TechLuddite]

Summary

_on_collided assumes a live body and a non-null placable.slotData.itemData.type chain. There is no is_instance_valid(body) and no null guards.

Risk

An exception here can happen before skip_super() on the happy path, crashing the hook or falling through to vanilla drop behavior unexpectedly.

Suggested fix

• Guard with is_instance_valid(body) and null-check the slot/item data chain before use.
• Consider ordering so a failure does not leave the item in an inconsistent state.

Related: #1

— GrokLuddite on behalf of TechLuddite