refactor: collapse per-env Configs into ClientEnv + ServerEnv (#3906)

## Description:

This is a refactor to simplify config handling.

Replaces the per-environment DevConfig/PreprodConfig/ProdConfig class
hierarchy with two static classes: ClientEnv (browser main thread, reads
from window.BOOTSTRAP_CONFIG) and ServerEnv (Node server, reads from
process.env). The four config classes are deleted, the abstract
DefaultServerConfig is gone, and DefaultConfig is renamed to Config.

The values that flow server → client (gameEnv, numWorkers,
turnstileSiteKey, jwtAudience, instanceId) used to be baked into the
hardcoded per-env classes. They're now real env vars on the server,
embedded into a single window.BOOTSTRAP_CONFIG object in index.html at
request time (alongside the existing gitCommit/assetManifest/cdnBase
globals, which moved into the same object), and read back by ClientEnv
on the client. The dev defaults previously hidden inside DevServerConfig
are now explicit in start:server-dev (NUM_WORKERS=2,
TURNSTILE_SITE_KEY=1x..., JWT_AUDIENCE=localhost, etc.) and in
vite.config.ts's html plugin inject.data. Production deploys plumb
NUM_WORKERS and TURNSTILE_SITE_KEY through deploy.yml (GitHub vars) into
the remote env file; JWT_AUDIENCE is derived from DOMAIN in deploy.sh.
The dynamic /api/instance endpoint is gone — INSTANCE_ID rides along in
BOOTSTRAP_CONFIG now.

ServerEnv is the only thing server code touches; ClientEnv is
browser-only. The two classes have intentional overlap (env, numWorkers,
jwtIssuer, gameCreationRate, workerIndex, etc.) since they derive
identical logic from different sources — there's a TODO in each to
consolidate via a shared helper later. The game-logic Config no longer
stores a ServerConfig/ClientEnv reference and its serverConfig() getter
is gone; the one caller (MultiTabModal) now reads ClientEnv.env()
directly. Worker init no longer carries server-config values since
nothing in the worker actually reads them.

## 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:

evan

src/client/graphics/AnimatedSpriteLoader.ts

@@ -1,3 +1,4 @@
+import { Theme } from "src/core/configuration/Theme";
 import miniBigSmoke from "../../../resources/sprites/bigsmoke.png";
 import buildingExplosion from "../../../resources/sprites/buildingExplosion.png";
 import conquestSword from "../../../resources/sprites/conquestSword.png";
@@ -10,7 +11,6 @@ import sinkingShip from "../../../resources/sprites/sinkingShip.png";
 import miniSmoke from "../../../resources/sprites/smoke.png";
 import miniSmokeAndFire from "../../../resources/sprites/smokeAndFire.png";
 import unitExplosion from "../../../resources/sprites/unitExplosion.png";
-import { Theme } from "../../core/configuration/Config";
 import { PlayerView } from "../../core/game/GameView";
 import { AnimatedSprite } from "./AnimatedSprite";
 import { FxType } from "./fx/Fx";

src/client/graphics/SpriteLoader.ts

@@ -1,6 +1,6 @@
 import { Colord } from "colord";
+import { Theme } from "src/core/configuration/Theme";
 import { assetUrl } from "../../core/AssetUrls";
-import { Theme } from "../../core/configuration/Config";
 import { TrainType, UnitType } from "../../core/game/Game";
 import { UnitView } from "../../core/game/GameView";
 const atomBombSprite = assetUrl("sprites/atombomb.png");

src/client/graphics/fx/SpriteFx.ts

@@ -1,4 +1,4 @@
-import { Theme } from "../../../core/configuration/Config";
+import { Theme } from "src/core/configuration/Theme";
 import { PlayerView } from "../../../core/game/GameView";
 import { AnimatedSprite } from "../AnimatedSprite";
 import { AnimatedSpriteLoader } from "../AnimatedSpriteLoader";

src/client/graphics/layers/FxLayer.ts

@@ -1,4 +1,4 @@
-import { Theme } from "../../../core/configuration/Config";
+import { Theme } from "src/core/configuration/Theme";
 import { EventBus } from "../../../core/EventBus";
 import { UnitType } from "../../../core/game/Game";
 import { TileRef } from "../../../core/game/GameMap";

src/client/graphics/layers/MultiTabModal.ts

@@ -1,5 +1,6 @@
 import { LitElement, html } from "lit";
 import { customElement, property, state } from "lit/decorators.js";
+import { ClientEnv } from "src/client/ClientEnv";
 import { GameEnv } from "../../../core/configuration/Config";
 import { GameType } from "../../../core/game/Game";
 import { GameView } from "../../../core/game/GameView";
@@ -31,7 +32,7 @@ export class MultiTabModal extends LitElement implements Layer {
     if (
       this.game.inSpawnPhase() ||
       this.game.config().gameConfig().gameType === GameType.Singleplayer ||
-      this.game.config().serverConfig().env() === GameEnv.Dev ||
+      ClientEnv.env() === GameEnv.Dev ||
       this.game.config().isReplay()
     ) {
       return;

src/client/graphics/layers/NameLayer.ts

@@ -1,7 +1,8 @@
 import { assetUrl } from "src/core/AssetUrls";
+import { Theme } from "src/core/configuration/Theme";
 import { EventBus } from "../../../core/EventBus";
 import { PseudoRandom } from "../../../core/PseudoRandom";
-import { Config, Theme } from "../../../core/configuration/Config";
+import { Config } from "../../../core/configuration/Config";
 import { Cell } from "../../../core/game/Game";
 import { GameView, PlayerView } from "../../../core/game/GameView";
 import { UserSettings } from "../../../core/game/UserSettings";

src/client/graphics/layers/StructureDrawingUtils.ts

@@ -1,6 +1,6 @@
 import * as PIXI from "pixi.js";
+import { Theme } from "src/core/configuration/Theme";
 import { assetUrl } from "../../../core/AssetUrls";
-import { Theme } from "../../../core/configuration/Config";
 import {
   Cell,
   PlayerBuildableUnitType,

src/client/graphics/layers/StructureIconsLayer.ts

@@ -2,8 +2,8 @@ import { extend } from "colord";
 import a11yPlugin from "colord/plugins/a11y";
 import { OutlineFilter } from "pixi-filters";
 import * as PIXI from "pixi.js";
+import { Theme } from "src/core/configuration/Theme";
 import { assetUrl } from "../../../core/AssetUrls";
-import { Theme } from "../../../core/configuration/Config";
 import { EventBus } from "../../../core/EventBus";
 import { wouldNukeBreakAlliance } from "../../../core/execution/Util";
 import {

src/client/graphics/layers/StructureLayer.ts

@@ -1,6 +1,6 @@
 import { colord, Colord } from "colord";
+import { Theme } from "src/core/configuration/Theme";
 import { assetUrl } from "../../../core/AssetUrls";
-import { Theme } from "../../../core/configuration/Config";
 import { EventBus } from "../../../core/EventBus";
 import { TransformHandler } from "../TransformHandler";
 import { Layer } from "./Layer";

src/client/graphics/layers/TerrainLayer.ts

@@ -1,4 +1,5 @@
-import { Config, Theme } from "../../../core/configuration/Config";
+import { Theme } from "src/core/configuration/Theme";
+import { Config } from "../../../core/configuration/Config";
 import { GameView } from "../../../core/game/GameView";
 import { TransformHandler } from "../TransformHandler";
 import { Layer } from "./Layer";

src/client/graphics/layers/TerritoryLayer.ts

@@ -1,6 +1,6 @@
 import { PriorityQueue } from "@datastructures-js/priority-queue";
 import { Colord } from "colord";
-import { Theme } from "../../../core/configuration/Config";
+import { Theme } from "src/core/configuration/Theme";
 import { EventBus } from "../../../core/EventBus";
 import {
   Cell,

src/client/graphics/layers/UILayer.ts

@@ -1,6 +1,6 @@
 import { Colord } from "colord";
+import { Theme } from "src/core/configuration/Theme";
 import { EventBus } from "../../../core/EventBus";
-import { Theme } from "../../../core/configuration/Config";
 import { UnitType } from "../../../core/game/Game";
 import { GameUpdateType } from "../../../core/game/GameUpdates";
 import { GameView, UnitView } from "../../../core/game/GameView";

src/client/graphics/layers/UnitLayer.ts

@@ -1,6 +1,6 @@
 import { colord, Colord } from "colord";
+import { Theme } from "src/core/configuration/Theme";
 import { EventBus } from "../../../core/EventBus";
-import { Theme } from "../../../core/configuration/Config";
 import { Cell, UnitType } from "../../../core/game/Game";
 import { TileRef } from "../../../core/game/GameMap";
 import { GameView, UnitView } from "../../../core/game/GameView";