feat(playlist): add the Doomsday Clock to the public modifier rotation (#4589)

## Description:

Adds the anti-stall **Doomsday Clock** to the public "special" modifier
rotation, so it rolls into public games like the other spice modifiers,
with a lobby badge.

- `MapPlaylist`: new `isDoomsdayClock` ticket in `SPECIAL_MODIFIER_POOL`
(weight 4, ~20% of special games). When rolled, enables `doomsdayClock`
at a speed picked per game (slow/normal/fast/veryfast).
- `PublicGameModifiers` (type + schema): `isDoomsdayClock` flag drives
the badge.
- `getActiveModifiers` + `en.json`: a "Doomsday Clock" badge/label.
- Test covering the badge wiring.

## 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

src/core/Schemas.ts

@@ -328,6 +328,7 @@ export const GameConfigSchema = z.object({
       isSAMsDisabled: z.boolean().optional(),
       isPeaceTime: z.boolean().optional(),
       isWaterNukes: z.boolean().optional(),
+      isDoomsdayClock: z.boolean().optional(),
     })
     .optional(),
   nations: z

src/core/game/Game.ts

@@ -148,6 +148,7 @@ export interface PublicGameModifiers {
   isSAMsDisabled?: boolean;
   isPeaceTime?: boolean;
   isWaterNukes?: boolean;
+  isDoomsdayClock?: boolean;
 }
 
 export interface UnitInfo {