Added pause functionality for private multiplayer games (#2657)

If this PR fixes an issue, link it below. If not, delete these two
lines.
Resolves #2491

## Description:
Adds pause/unpause functionality for private multiplayer games. Only the
lobby creator can pause the game, and all players see a pause overlay
when the game is paused.

  **Key features:**
- Lobby creator sees pause/play button in control panel (alongside
existing singleplayer/replay controls)
  - Server validates that only lobby creator can toggle pause
  - All players see "Game paused by Lobby Creator" overlay when paused
  - Game state freezes (no turn execution) while paused
  - Unpause resumes normal gameplay

  **Implementation details:**
- Server-side pause state (`isPaused`) prevents turn execution during
pause
- Each client receives `isLobbyCreator` flag in `GameStartInfo` to
show/hide pause button
- Added `TogglePauseIntent` that broadcasts to all clients via
`NoOpExecution`
  - New `PauseOverlay` component (shows in single player also)

## 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:

furo18

<img width="1459" height="861" alt="Screenshot 2025-12-20 at 15 16 33"
src="https://github.com/user-attachments/assets/f5a3222f-f54b-473c-b0f6-104ce4c1e7a8"
/>

src/client/graphics/layers/SettingsModal.ts

@@ -15,7 +15,7 @@ import musicIcon from "../../../../resources/images/music.svg";
 import { EventBus } from "../../../core/EventBus";
 import { UserSettings } from "../../../core/game/UserSettings";
 import { AlternateViewEvent, RefreshGraphicsEvent } from "../../InputHandler";
-import { PauseGameEvent } from "../../Transport";
+import { PauseGameIntentEvent } from "../../Transport";
 import { translateText } from "../../Utils";
 import SoundManager from "../../sound/SoundManager";
 import { Layer } from "./Layer";
@@ -108,7 +108,7 @@ export class SettingsModal extends LitElement implements Layer {
 
   private pauseGame(pause: boolean) {
     if (this.shouldPause && !this.wasPausedWhenOpened)
-      this.eventBus.emit(new PauseGameEvent(pause));
+      this.eventBus.emit(new PauseGameIntentEvent(pause));
   }
 
   private onTerrainButtonClick() {