New Map! "Four Islands" 🏝️ (#2482)

## Description:

Made a type of map we don't already have: Small square map, one Island
in each corner. Could be great for boat gameplay or maybe even nuke
wars.

The special thing is: **All islands are exactly 25% of the territory!**
Was a lot of work drawing that in GIMP...

<img width="1164" height="1168" alt="Screenshot 2025-11-20 000839"
src="https://github.com/user-attachments/assets/ad8345c7-562d-49e8-b367-12be9274f3e4"
/>

<img width="1227" height="1222" alt="Screenshot 2025-11-20 000633"
src="https://github.com/user-attachments/assets/f7e2c58a-fcb3-4e07-91f2-aead5f497fad"
/>

<img width="361" height="288" alt="Screenshot 2025-11-20 000655"
src="https://github.com/user-attachments/assets/120f82ef-2d19-497b-8a31-819e30013c89"
/>

<img width="756" height="282" alt="Screenshot 2025-11-20 005949"
src="https://github.com/user-attachments/assets/8ee04da3-d5fa-4ec9-9e99-9e30ebda2b78"
/>

## 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

---------

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

src/client/components/Maps.ts

@@ -38,6 +38,7 @@ export const MapDescription: Record<keyof typeof GameMapType, string> = {
   Montreal: "Montreal",
   Achiran: "Achiran",
   BaikalNukeWars: "Baikal (Nuke Wars)",
+  FourIslands: "Four Islands",
 };
 
 @customElement("map-display")

src/core/configuration/DefaultConfig.ts

@@ -60,6 +60,7 @@ const numPlayersConfig = {
   [GameMapType.Europe]: [100, 70, 50],
   [GameMapType.EuropeClassic]: [50, 30, 30],
   [GameMapType.FalklandIslands]: [50, 30, 20],
+  [GameMapType.FourIslands]: [20, 15, 10],
   [GameMapType.FaroeIslands]: [20, 15, 10],
   [GameMapType.GatewayToTheAtlantic]: [100, 70, 50],
   [GameMapType.GiantWorldMap]: [100, 70, 50],

src/core/game/Game.ts

@@ -101,6 +101,7 @@ export enum GameMapType {
   Montreal = "Montreal",
   Achiran = "Achiran",
   BaikalNukeWars = "Baikal (Nuke Wars)",
+  FourIslands = "Four Islands",
 }
 
 export type GameMapName = keyof typeof GameMapType;
@@ -143,6 +144,7 @@ export const mapCategories: Record<string, GameMapType[]> = {
     GameMapType.DeglaciatedAntarctica,
     GameMapType.Achiran,
     GameMapType.BaikalNukeWars,
+    GameMapType.FourIslands,
   ],
 };