Allow NUM_WORKERS override (#2776)

Resolves #2610

## Description:

Add NUM_WORKERS env override for server worker count.

## 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:
aotumuri

---------

Co-authored-by: Evan <evanpelle@gmail.com>

src/core/configuration/DefaultConfig.ts

@@ -164,7 +164,17 @@ export abstract class DefaultServerConfig implements ServerConfig {
     }
     return token;
   }
-  abstract numWorkers(): number;
+  numWorkers(): number {
+    const raw = Env.NUM_WORKERS;
+    if (!raw) {
+      throw new Error("NUM_WORKERS not set");
+    }
+    const parsed = Number(raw);
+    if (!Number.isFinite(parsed) || parsed <= 0) {
+      throw new Error(`Invalid NUM_WORKERS value "${raw}"`);
+    }
+    return Math.floor(parsed);
+  }
   abstract env(): GameEnv;
   turnIntervalMs(): number {
     return 100;

src/core/configuration/DevConfig.ts

@@ -27,7 +27,6 @@ export class DevServerConfig extends DefaultServerConfig {
   gameCreationRate(): number {
     return 5 * 1000;
   }
-
   numWorkers(): number {
     return 2;
   }

src/core/configuration/Env.ts

@@ -89,4 +89,7 @@ export const Env = {
   get ADMIN_TOKEN() {
     return getEnv("ADMIN_TOKEN");
   },
+  get NUM_WORKERS() {
+    return getEnv("NUM_WORKERS");
+  },
 };

src/core/configuration/PreprodConfig.ts

@@ -5,9 +5,6 @@ export const preprodConfig = new (class extends DefaultServerConfig {
   env(): GameEnv {
     return GameEnv.Preprod;
   }
-  numWorkers(): number {
-    return 2;
-  }
   turnstileSiteKey(): string {
     return "0x4AAAAAAB7QetxHwRCKw-aP";
   }

src/core/configuration/ProdConfig.ts

@@ -2,9 +2,6 @@ import { GameEnv } from "./Config";
 import { DefaultServerConfig } from "./DefaultConfig";
 
 export const prodConfig = new (class extends DefaultServerConfig {
-  numWorkers(): number {
-    return 20;
-  }
   env(): GameEnv {
     return GameEnv.Prod;
   }