Feature/colorblind mode (#4150)

**Add approved & assigned issue number here:**

Resolves #2549

## Description:

Adds colorblind mode. Similar to dark mode, it exists as a toggle in
settings. When enabled, it swaps the game's theme (which is refactored
to extend from a theme base class) to use more colorblind-friendly
colors and brightness variations. Borders are darkened, and terrarin is
separated by lightness. Friendly/Foe colors and switched to blue/orange
instead of red/green.

The theme refactor supports adding new themes without having to
reimplement the color distribution system. New themes can extend the
BaseTheme and supply the data, such as palettes, team-color variations,
and terrain.

New setting:
<img width="880" height="273" alt="Screenshot 2026-06-04 at 11 30 27 AM"
src="https://github.com/user-attachments/assets/d5d573d5-cc64-4ac1-95c2-00627faf17cc"
/>

New color palette:
<img width="1119" height="757" alt="Screenshot 2026-06-04 at 11 30
59 AM"
src="https://github.com/user-attachments/assets/2bb15bc9-992b-41ae-ab0e-b01fe0c3c6bb"
/>

## 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

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

jetaviz

src/client/view/GameView.ts

@@ -872,6 +872,17 @@ export class GameView implements GameMap {
     return Array.from(this._players.values());
   }
 
+  /**
+   * Recompute every player's theme-derived colors. Call when the active theme
+   * changes mid-game (e.g. toggling colorblind mode) so existing territories
+   * re-color; the renderer palette must be refreshed afterwards.
+   */
+  refreshPlayerColors(): void {
+    for (const p of this._players.values()) {
+      p.refreshColors();
+    }
+  }
+
   playerBySmallID(id: number): PlayerView | TerraNullius {
     if (id === 0) {
       return new TerraNulliusImpl();

src/client/view/PlayerView.ts

@@ -105,19 +105,20 @@ export class PlayerView {
   /** Static header data — set once at construction, never mutated. */
   public static: PlayerStatic;
 
-  private _territoryColor: Colord;
-  private _borderColor: Colord;
-  private _railColor: Colord;
+  // Assigned via computeColors() in the constructor; re-assignable on theme change.
+  private _territoryColor!: Colord;
+  private _borderColor!: Colord;
+  private _railColor!: Colord;
   // Update here to include structure light and dark colors
-  private _structureColors: { light: Colord; dark: Colord };
+  private _structureColors!: { light: Colord; dark: Colord };
 
   // Pre-computed border color variants
-  private _borderColorNeutral: Colord;
-  private _borderColorFriendly: Colord;
-  private _borderColorEmbargo: Colord;
-  private _borderColorDefendedNeutral: { light: Colord; dark: Colord };
-  private _borderColorDefendedFriendly: { light: Colord; dark: Colord };
-  private _borderColorDefendedEmbargo: { light: Colord; dark: Colord };
+  private _borderColorNeutral!: Colord;
+  private _borderColorFriendly!: Colord;
+  private _borderColorEmbargo!: Colord;
+  private _borderColorDefendedNeutral!: { light: Colord; dark: Colord };
+  private _borderColorDefendedFriendly!: { light: Colord; dark: Colord };
+  private _borderColorDefendedEmbargo!: { light: Colord; dark: Colord };
 
   constructor(
     private game: GameView,
@@ -135,6 +136,23 @@ export class PlayerView {
       this.anonymousName = createRandomName(data.name!, data.playerType!);
     }
 
+    this.computeColors();
+
+    const pattern = userSettings.territoryPatterns()
+      ? this.cosmetics.pattern
+      : undefined;
+    this.decoder =
+      pattern === undefined
+        ? undefined
+        : new PatternDecoder(pattern, base64url.decode);
+  }
+
+  /**
+   * Compute every theme-derived color (fill, border, structure, and the
+   * neutral/friendly/embargo border variants) from the active theme. Re-callable
+   * so a mid-game theme change — e.g. toggling colorblind mode — can refresh them.
+   */
+  private computeColors(): void {
     const theme = themeProvider.current();
 
     const defaultTerritoryColor = theme.territoryColor(this);
@@ -164,7 +182,7 @@ export class PlayerView {
     this._structureColors = theme.structureColors(this._territoryColor);
 
     const maybeFocusedBorderColor =
-      this.game.myClientID() === data.clientID
+      this.game.myClientID() === this.static.clientID
         ? theme.focusedBorderColor()
         : defaultBorderColor;
 
@@ -230,11 +248,11 @@ export class PlayerView {
     this._borderColorDefendedEmbargo = theme.defendedBorderColors(
       this._borderColorEmbargo,
     );
+  }
 
-    this.decoder =
-      pattern === undefined
-        ? undefined
-        : new PatternDecoder(pattern, base64url.decode);
+  /** Recompute colors after the active theme changes (e.g. colorblind toggle). */
+  refreshColors(): void {
+    this.computeColors();
   }
 
   /**