- Add `defaultToMaxLength` + `resolveLength` for `ResizableSquareAbility`
- Switch Neon wall to `ResizableSquareAbility` and enable max-length defaults for Neon/Cypher walls
- Apply resolved length in `PlacedAbilityWidget` so initial handle position is correct
- Make `MouseWatch` clear hover state safely during dispose using cached container
- Add widget/unit tests for length resolution and Neon/Cypher defaults