More has_skill checks
Apply some responsibility separation
Expand action_limit to action_transform.

* and extract game logic out of UIDoActionStage and
    UIDoPassiveAction
Sanae: Skill tune.
Yuuka: Skill tune.
DonationBox ui_meta fix.
Tunable credits/drops policy
Fix skill category.

* active/passive: does this skill need skill button to operate?
SpFlandre skill tune.
incr ver, welcome msg.