Add SoundEffectController to restore v31 sound effects

Ports the sound-emission logic from v31's deleted FxLayer into a new
controller registered with the game renderer. Per-tick it scans the
worker's update stream and emits PlaySoundEffectEvent for unit launches,
nuke detonations, structure/warship builds (local player only), and
conquests where the local player is the conqueror.

src/client/controllers/SoundEffectController.ts

@@ -0,0 +1,87 @@
+import { EventBus } from "../../core/EventBus";
+import { UnitType } from "../../core/game/Game";
+import { GameUpdateType } from "../../core/game/GameUpdates";
+import { GameView, UnitView } from "../../core/game/GameView";
+import { Controller } from "../Controller";
+import { PlaySoundEffectEvent, SoundEffect } from "../sound/Sounds";
+
+export class SoundEffectController implements Controller {
+  constructor(
+    private readonly game: GameView,
+    private readonly eventBus: EventBus,
+  ) {}
+
+  tick(): void {
+    const updates = this.game.updatesSinceLastTick();
+    if (!updates) return;
+
+    for (const u of updates[GameUpdateType.Unit] ?? []) {
+      const unit = this.game.unit(u.id);
+      if (unit === undefined) continue;
+      this.handleUnit(unit);
+    }
+
+    const myPlayer = this.game.myPlayer();
+    if (myPlayer === null) return;
+    for (const c of updates[GameUpdateType.ConquestEvent] ?? []) {
+      if (c.conquerorId === myPlayer.id()) {
+        this.emit("ka-ching");
+      }
+    }
+  }
+
+  private handleUnit(unit: UnitView): void {
+    if (unit.isActive() && unit.createdAt() === this.game.ticks()) {
+      this.onCreated(unit);
+    }
+    switch (unit.type()) {
+      case UnitType.AtomBomb:
+      case UnitType.MIRVWarhead:
+        this.onNukeDetonation(unit, "atom-hit");
+        break;
+      case UnitType.HydrogenBomb:
+        this.onNukeDetonation(unit, "hydrogen-hit");
+        break;
+    }
+  }
+
+  private onCreated(unit: UnitView): void {
+    const myPlayer = this.game.myPlayer();
+    switch (unit.type()) {
+      case UnitType.AtomBomb:
+        this.emit("atom-launch");
+        break;
+      case UnitType.HydrogenBomb:
+        this.emit("hydrogen-launch");
+        break;
+      case UnitType.MIRV:
+        this.emit("mirv-launch");
+        break;
+      case UnitType.Warship:
+        if (unit.owner() === myPlayer) this.emit("build-warship");
+        break;
+      case UnitType.City:
+        if (unit.owner() === myPlayer) this.emit("build-city");
+        break;
+      case UnitType.Port:
+        if (unit.owner() === myPlayer) this.emit("build-port");
+        break;
+      case UnitType.DefensePost:
+        if (unit.owner() === myPlayer) this.emit("build-defense-post");
+        break;
+      case UnitType.SAMLauncher:
+        if (unit.owner() === myPlayer) this.emit("sam-built");
+        break;
+    }
+  }
+
+  private onNukeDetonation(unit: UnitView, sound: SoundEffect): void {
+    if (unit.isActive()) return;
+    if (!unit.reachedTarget()) return;
+    this.emit(sound);
+  }
+
+  private emit(sound: SoundEffect): void {
+    this.eventBus.emit(new PlaySoundEffectEvent(sound));
+  }
+}

src/client/hud/GameRenderer.ts

@@ -8,6 +8,7 @@ import { UIState } from "../UIState";
 import { AttackingTroopsController } from "../controllers/AttackingTroopsController";
 import { BuildPreviewController } from "../controllers/BuildPreviewController";
 import { HoverHighlightController } from "../controllers/HoverHighlightController";
+import { SoundEffectController } from "../controllers/SoundEffectController";
 import { StructureHighlightController } from "../controllers/StructureHighlightController";
 import { ViewModeController } from "../controllers/ViewModeController";
 import { WarshipSelectionController } from "../controllers/WarshipSelectionController";
@@ -294,6 +295,7 @@ export function createRenderer(
     new StructureHighlightController(eventBus, view),
     new ViewModeController(eventBus, view),
     new AttackingTroopsController(game, eventBus, userSettings, view),
+    new SoundEffectController(game, eventBus),
     eventsDisplay,
     actionableEvents,
     attacksDisplay,