Kart Racing

1.0.1 - course generation fixes (Grand Prix and races)

• Fixed: Grand Prix course generation failed (or ground on for an hour) on many world seeds. The End-stage circuit planner was racing vanilla's own End machinery; planning now completes atomically. Verified on the reported seeds.
• New: generation that cannot succeed now fails within a few minutes with a clear message instead of stalling at a progress percentage.
• Known limitation: on rare seeds the stronghold road cannot be routed; retrying on another world works. Overworld races are unaffected.
• Note: the server may still pause for a few seconds during the End-stage planning step; the heavy road planning no longer blocks it (see below).
• Fixed: race checkpoints could be placed on open water where karts cannot drive; checkpoints now prefer dry ground and creation fails clearly when no safe surface exists.
• Fixed: checkpoint gates that do touch water sank below the surface; they float on it again.
• Changed: the client-side spectator camera helper moved from /mkr spectate to /mkrspectate (same subcommands). The Q key flow is unaffected.
• Improved: when the stronghold road cannot resolve a crossing, generation now retries with a narrower curve before giving up -- some previously failing world/start combinations succeed.
• Improved: the heavy stronghold/nether road planning now runs off the main thread again (the End stage stays single-tick for correctness), so servers keep ticking while a Grand Prix course is planned.