Add host cheats for streamers (Specifically Enzo) ⭐ (#3671)

## Description:

- Adds a "Host Cheats" toggle in the private lobby options section that
reveals a dedicated section with four host-only cheats: infinite gold,
infinite troops, gold multiplier, and starting gold
- Only the lobby creator receives the cheat effects in-game (checked via
`isLobbyCreator` in DefaultConfig)
- Joining players see active host cheats displayed as yellow badges in
the lobby UI
- Adds `hostCheats` optional object to `GameConfigSchema` and wires it
through the server config update whitelist
- Raises the intent size limit for `update_game_config` messages
(lobby-only, not stored in turn history) to prevent rate-limiter kicks
(I always got too-much-data-kicked after selecting "host cheats" lol)

<img width="861" height="525" alt="image"
src="https://github.com/user-attachments/assets/51e51ec4-c2e8-46ca-b258-11a93487964f"
/>


<img width="933" height="825" alt="image"
src="https://github.com/user-attachments/assets/5acbd38d-2097-42e1-ba78-0fb17d6afe82"
/>

## Please complete the following:

- [X] I have added screenshots for all UI updates
- [X] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [X] I have added relevant tests to the test directory
- [X] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## Please put your Discord username so you can be contacted if a bug or
regression is found:

FloPinguin

src/core/configuration/Config.ts

@@ -128,7 +128,7 @@ export interface Config {
   defaultDonationAmount(sender: Player): number;
   unitInfo(type: UnitType): UnitInfo;
   tradeShipShortRangeDebuff(): number;
-  tradeShipGold(dist: number): Gold;
+  tradeShipGold(dist: number, player: Player | PlayerView): Gold;
   tradeShipSpawnRate(
     tradeShipSpawnRejections: number,
     numTradeShips: number,
@@ -136,6 +136,7 @@ export interface Config {
   trainGold(
     rel: "self" | "team" | "ally" | "other",
     citiesVisited: number,
+    player: Player | PlayerView,
   ): Gold;
   trainSpawnRate(numPlayerFactories: number): number;
   trainStationMinRange(): number;

src/core/configuration/DefaultConfig.ts

@@ -271,7 +271,7 @@ export class DefaultConfig implements Config {
     if (playerInfo.playerType === PlayerType.Bot) {
       return 0n;
     }
-    return BigInt(this._gameConfig.startingGold ?? 0);
+    return this.startingGoldFor(playerInfo);
   }
 
   trainSpawnRate(numPlayerFactories: number): number {
@@ -282,6 +282,7 @@ export class DefaultConfig implements Config {
   trainGold(
     rel: "self" | "team" | "ally" | "other",
     citiesVisited: number,
+    player: Player | PlayerView,
   ): Gold {
     // No penalty for the first 10 cities.
     citiesVisited = Math.max(0, citiesVisited - 9);
@@ -300,7 +301,7 @@ export class DefaultConfig implements Config {
     }
     const distPenalty = citiesVisited * 5_000;
     const gold = Math.max(5000, baseGold - distPenalty);
-    return toInt(gold * this.goldMultiplier());
+    return toInt(gold * this.goldMultiplierFor(player));
   }
 
   trainStationMinRange(): number {
@@ -313,13 +314,12 @@ export class DefaultConfig implements Config {
     return 120;
   }
 
-  tradeShipGold(dist: number): Gold {
+  tradeShipGold(dist: number, player: Player | PlayerView): Gold {
     // Sigmoid: concave start, sharp S-curve middle, linear end - heavily punishes trades under range debuff.
     const debuff = this.tradeShipShortRangeDebuff();
     const baseGold =
       75_000 / (1 + Math.exp(-0.03 * (dist - debuff))) + 50 * dist;
-    const multiplier = this.goldMultiplier();
-    return BigInt(Math.floor(baseGold * multiplier));
+    return BigInt(Math.floor(baseGold * this.goldMultiplierFor(player)));
   }
 
   // Probability of trade ship spawn = 1 / tradeShipSpawnRate
@@ -396,7 +396,10 @@ export class DefaultConfig implements Config {
       case UnitType.MIRV:
         info = {
           cost: (game: Game, player: Player) => {
-            if (player.type() === PlayerType.Human && this.infiniteGold()) {
+            if (
+              player.type() === PlayerType.Human &&
+              this.hasInfiniteGoldFor(player)
+            ) {
               return 0n;
             }
             return 25_000_000n + game.stats().numMirvsLaunched() * 15_000_000n;
@@ -478,12 +481,55 @@ export class DefaultConfig implements Config {
     return info;
   }
 
+  private hasInfiniteGoldFor(player: Player | PlayerView): boolean {
+    if (this.infiniteGold()) return true;
+    const hc = this._gameConfig.hostCheats;
+    return (hc?.infiniteGold ?? false) && player.isLobbyCreator();
+  }
+
+  private hasInfiniteTroopsFor(player: Player | PlayerView): boolean {
+    if (this.infiniteTroops()) return true;
+    return (
+      (this._gameConfig.hostCheats?.infiniteTroops ?? false) &&
+      player.isLobbyCreator()
+    );
+  }
+
+  private hasInfiniteTroopsForInfo(playerInfo: PlayerInfo): boolean {
+    if (this.infiniteTroops()) return true;
+    return (
+      (this._gameConfig.hostCheats?.infiniteTroops ?? false) &&
+      playerInfo.isLobbyCreator
+    );
+  }
+
+  private goldMultiplierFor(player: Player | PlayerView): number {
+    const base = this.goldMultiplier();
+    const hc = this._gameConfig.hostCheats;
+    if (hc?.goldMultiplier && player.isLobbyCreator()) {
+      return hc.goldMultiplier;
+    }
+    return base;
+  }
+
+  private startingGoldFor(playerInfo: PlayerInfo): Gold {
+    const base = BigInt(this._gameConfig.startingGold ?? 0);
+    const hc = this._gameConfig.hostCheats;
+    if (hc?.startingGold && playerInfo.isLobbyCreator) {
+      return base + BigInt(hc.startingGold);
+    }
+    return base;
+  }
+
   private costWrapper(
     costFn: (units: number) => number,
     ...types: UnitType[]
   ): (g: Game, p: Player) => bigint {
     return (game: Game, player: Player) => {
-      if (player.type() === PlayerType.Human && this.infiniteGold()) {
+      if (
+        player.type() === PlayerType.Human &&
+        this.hasInfiniteGoldFor(player)
+      ) {
         return 0n;
       }
       const numUnits = types.reduce(
@@ -761,12 +807,12 @@ export class DefaultConfig implements Config {
           assertNever(this._gameConfig.difficulty);
       }
     }
-    return this.infiniteTroops() ? 1_000_000 : 25_000;
+    return this.hasInfiniteTroopsForInfo(playerInfo) ? 1_000_000 : 25_000;
   }
 
   maxTroops(player: Player | PlayerView): number {
     const maxTroops =
-      player.type() === PlayerType.Human && this.infiniteTroops()
+      player.type() === PlayerType.Human && this.hasInfiniteTroopsFor(player)
         ? 1_000_000_000
         : 2 * (Math.pow(player.numTilesOwned(), 0.6) * 1000 + 50000) +
           player
@@ -833,7 +879,7 @@ export class DefaultConfig implements Config {
   }
 
   goldAdditionRate(player: Player): Gold {
-    const multiplier = this.goldMultiplier();
+    const multiplier = this.goldMultiplierFor(player);
     let baseRate: bigint;
     if (player.type() === PlayerType.Bot) {
       baseRate = 50n;