Add performance stats (#2338)

## Description:

Enhanced the performance overlay to display additional tick-related
performance metrics. The overlay now shows:

1. **Tick Execution Duration** - Average and maximum time (in
milliseconds) it takes to execute a game tick
2. **Tick Delay** - Average and maximum time (in milliseconds) between
receiving tick updates from the server

The server sends 10 updates per second (100ms interval), so these
metrics help identify:
- Client-side performance bottlenecks (tick execution duration)
- Network latency issues (tick delay)

**Additional improvements:**
- Renamed `FPSDisplay` component to `PerformanceOverlay` to better
reflect its expanded purpose
- Updated method names (`updateFPS` → `updateFrameMetrics`) and CSS
classes for consistency

All metrics are tracked over the last 60 ticks, providing rolling
averages and maximum values for performance analysis.

## Please complete the following:

- [x] I have added screenshots for all UI updates:
- <img width="495" height="227" alt="image"
src="https://github.com/user-attachments/assets/142b0313-61bf-46cc-b595-61fe73f6b54c"
/>


- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- Translation keys already exist in en.json for
"performance_overlay_label" and "performance_overlay_desc"

- [x] I have added relevant tests to the test directory
  - All existing tests pass (309/310 tests passed)
  - No new tests added as this is primarily a display enhancement

- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
  - Tested locally with npm test
  - Verified performance overlay displays all metrics correctly
  - Confirmed tick metrics are calculated and displayed accurately

## Please put your Discord username so you can be contacted if a bug or
regression is found:

Discord: kerverse

---------

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

src/core/GameRunner.ts

@@ -130,9 +130,13 @@ export class GameRunner {
     this.currTurn++;
 
     let updates: GameUpdates;
+    let tickExecutionDuration: number = 0;
 
     try {
+      const startTime = performance.now();
       updates = this.game.executeNextTick();
+      const endTime = performance.now();
+      tickExecutionDuration = endTime - startTime;
     } catch (error: unknown) {
       if (error instanceof Error) {
         console.error("Game tick error:", error.message);
@@ -173,6 +177,7 @@ export class GameRunner {
       packedTileUpdates: new BigUint64Array(packedTileUpdates),
       updates: updates,
       playerNameViewData: this.playerViewData,
+      tickExecutionDuration: tickExecutionDuration,
     });
     this.isExecuting = false;
   }

src/core/game/GameUpdates.ts

@@ -19,6 +19,7 @@ export interface GameUpdateViewData {
   updates: GameUpdates;
   packedTileUpdates: BigUint64Array;
   playerNameViewData: Record<string, NameViewData>;
+  tickExecutionDuration?: number;
 }
 
 export interface ErrorUpdate {