rename Layer → Controller; drop canvas2D-era interface hooks

The Layer interface dates to the canvas2D era when each entry drew to
the shared 2D context via renderLayer(ctx). With canvas2D gone, nothing
draws there and the renderLayer hook is dead. Rename the interface
("main-thread analog of the worker's Execution") and trim it:

  interface Controller {
    init?: () => void;
    tick?: () => void;
    getTickIntervalMs?: () => number;
  }

renderLayer / shouldTransform / redraw are gone.

Sweep across 28 files: from "./Layer" → "./Controller", implements
Layer → implements Controller, Layer[] / Map<Layer,…> →
Controller[] / Map<Controller,…>. Delete the no-op renderLayer +
shouldTransform method bodies that every layer had inherited.

GameRenderer drops the RedrawGraphicsEvent listener + redraw() fanout
(nothing implements redraw anymore) and the now-unused eventBus
constructor field.

One real case: AttackingTroopsOverlay.renderLayer wasn't a no-op — it
updates DOM label transforms each frame so labels track the WebGL
camera during pan/zoom. Rename to private updateLabelDOM() and start
a self-driven RAF in init() so the per-frame updates keep running.

Class names ending in "Layer" (UILayer, StructureIconsLayer, NameLayer,
etc.) intentionally left as-is — those are separate identifiers and
the class-rename / file-move is a follow-up.

407 tests pass.

src/client/graphics/layers/RadialMenu.ts

@@ -4,7 +4,7 @@ import { EventBus, GameEvent } from "../../../core/EventBus";
 import { CloseViewEvent } from "../../InputHandler";
 import { PlaySoundEffectEvent } from "../../sound/Sounds";
 import { getSvgAspectRatio, translateText } from "../../Utils";
-import { Layer } from "./Layer";
+import { Controller } from "./Controller";
 import {
   CenterButtonElement,
   MenuElement,
@@ -51,7 +51,7 @@ type CenterButtonState = "default" | "back";
 
 type RequiredRadialMenuConfig = Required<RadialMenuConfig>;
 
-export class RadialMenu implements Layer {
+export class RadialMenu implements Controller {
   private menuElement: d3.Selection<HTMLDivElement, unknown, null, undefined>;
   private tooltipElement: HTMLDivElement | null = null;
   private isVisible: boolean = false;
@@ -1341,14 +1341,6 @@ export class RadialMenu implements Layer {
     });
   }
 
-  renderLayer(context: CanvasRenderingContext2D) {
-    // No need to render anything on the canvas
-  }
-
-  shouldTransform(): boolean {
-    return false;
-  }
-
   private isReopeningAllowed(): boolean {
     const now = Date.now();
     const timeSinceHide = now - this.lastHideTime;