Liquid Memories can fail in headless due to missing Godot.Color overload

[CyberBarbarian]

Liquid Memories can be consumed in headless mode without opening the expected discard-pile card selection because a Godot color constructor overload is missing from the stubs.

Minimal repro shape:

1. Start Ironclad with LIQUID_MEMORIES.
2. Enter combat.
3. Play one or more cards so the discard pile has selectable cards.
4. Use Liquid Memories.

Observed before local patch:

• Potion slot was consumed.
• No card selection opened.
• stderr contained:

System.MissingMethodException: Method not found: 'Void Godot.Color..ctor(Godot.Color, Single)'

Expected:

• Liquid Memories should open a one-card discard-pile selection and then return the selected card to hand with the expected potion behavior.

This appears to be a headless Godot stub compatibility issue, not a potion logic issue. Our local patch added the missing Color(Color, float alpha) stub constructor.

Fork reference: CyberBarbarian@8cfba3d