Boost now turns faster

Boost has been upgraded to make high-speed movement feel more responsive in real battles.

What changed:

• While boost is active, the first turn command in each frame no longer spends that frame's action.
• This lets boosted tanks chain a 90-degree turn into movement in the same frame, such as turn followed by go.
• Only one turn can be free per frame. Extra turns still spend the action, so boosted tanks cannot spin indefinitely for free.
• The same rule is active across 1v1 battles, multiplayer battles, and 3v3 team battles.

The intent is to reward tanks that plan corners, dodges, and star routes around boost timing without making unlimited turning possible.