Simple Challenge Roulette

- New "Race" co-op mode — multiple players search for the same item simultaneously on the same server, each independently. The first to find gets a chat announcement, and when everyone finds it, a leaderboard is displayed with each player's time.

- How to enable: on the Roulette screen (item selection), click the "Solo" button in the bottom-left corner — it toggles to "Race". Go through the item and modifier roulettes, then on the Preview screen click "Create World". After the world loads, open it to LAN (Esc → "Open to LAN"), and your friend can join via LAN to participate in the race.

- The Solo/Race toggle now has a colored border and pulsing glow in Race mode for better visibility.

- Race mode indicator shown on the Preview screen.

- Timer synced to all players every second (20 ticks) during a race.

- Each player's finish time is stored individually — the Victory screen shows your own time, not the global race time.

- The race winner gets +1 to the win counter.

- Race HUD: shows all participants on screen with their status (✓ found / ⏳ searching) and finish time for those who found it. Current player is highlighted with a yellow » icon.

- Sound on find: when another player finds the item, everyone else hears a notification sound.

- Countdown before start: loading a race world starts with a 3... 2... 1... GO! countdown. All players start simultaneously.

- Live position on HUD: your current rank (1/4, 2/4...) is displayed in real time during the race, adapted to the selected HUD theme.

- All 4 HUD themes (Classic, Slim, Glow, Minimal) support the racer list and position display.

- Configurable countdown duration — set from 1 to 30 seconds in config (Race Mode → Race Countdown Seconds). The countdown display shows the actual remaining time.

- Configurable minimum players — configurable in config (Race Mode → Min Players for Countdown). The countdown only starts when enough players are online.

- Spectator mode while waiting: until enough players join, everyone is in spectator mode — cannot break blocks, place blocks, or interact with the world. New players also join as spectators.

- Safe spawn teleport on GO! — when the countdown reaches GO!, all players are teleported to world spawn (above the highest solid block) before switching to survival.

- Countdown abort on player leave: if someone disconnects during countdown and the player count drops below minimum, the countdown is cancelled and everyone returns to waiting mode.

- Smooth animated countdown rendering: number appears with a pop animation, pulsing border glow, color transitions from white → yellow → orange → red. GO! with a golden flash.

- Waiting message: players see "Waiting for players... Race starts when X players are online."

- Chat leaderboard: decorated with gold borders, medal prefixes for top 3 (gold / silver / bronze).

- 5 new HUD themes: Pixel (8-bit art), Retro (VHS horror), Thermal (infrared gradient) — 7 themes total.

- Theme preview in config: when editing HUD Theme, a miniature (260×80px) is shown with accurate visual styling: background color, borders, scanlines (Pixel), VHS glitch (Retro), thermal gradient (Thermal), neon cycling (Glow).

- Cycle button: replaced the text field with a ◀ Classic ▶ button — more intuitive and prevents typos.

- New "Race Mode" config category with min players and countdown duration settings. All settings translated into 6 languages.

- Fixed: countdown no longer resets when a new player joins — they simply see the remaining time.

- Fixed: player count check only runs for the Overworld dimension — no false triggers from other dimensions.