Add Mediterranean map (#3523)

## Description:

Adds Mediterranean sea map, from Iberia to Asia. Map contains ancient
Roman Empire provinces and its rivals as Nations.
This map was requested by the dev.

elevation data from Opentopography

<img width="2850" height="1450" alt="image"
src="https://github.com/user-attachments/assets/6aa5ba12-f4f7-414d-a712-b90323f1d796"
/>
<img width="590" height="304" alt="Captura de pantalla 2026-03-27
010038"
src="https://github.com/user-attachments/assets/efd1deea-bd88-4ae2-92a0-47a6626a0c0f"
/>
<img width="585" height="302" alt="Captura de pantalla 2026-03-27
005758"
src="https://github.com/user-attachments/assets/a127696e-fe34-424c-a88d-b86b99a5f414"
/>



## 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:

tri.star1011

src/core/game/Game.ts

@@ -144,6 +144,7 @@ export enum GameMapType {
   SanFrancisco = "San Francisco",
   Aegean = "Aegean",
   MilkyWay = "MilkyWay",
+  Mediterranean = "Mediterranean",
 }
 
 export type GameMapName = keyof typeof GameMapType;
@@ -195,6 +196,7 @@ export const mapCategories: Record<string, GameMapType[]> = {
     GameMapType.Arctic,
     GameMapType.SanFrancisco,
     GameMapType.Aegean,
+    GameMapType.Mediterranean,
   ],
   fantasy: [
     GameMapType.Pangaea,