delete dead canvas2D utilities, rename mountWebGLDebugRenderer → mountWebGLFrameLoop

ProgressBar and StructureDrawingUtils had no production callers — only
their own test referenced ProgressBar, and StructureDrawingUtils was a
canvas2D-era helper module that nothing imports anymore.

mountWebGLDebugRenderer was named back when WebGL was a side-by-side
debug overlay; it's the only renderer now, so the "Debug" prefix is
misleading. Also dropped the `\` keybind that hid the GL canvas — with
no other renderer, hiding it just blanks the game.

tests/client/graphics/ProgressBar.test.ts

@@ -1,55 +0,0 @@
-import { ProgressBar } from "../../../src/client/graphics/ProgressBar";
-
-describe("ProgressBar", () => {
-  let ctx: CanvasRenderingContext2D;
-  let canvas: HTMLCanvasElement;
-
-  beforeEach(() => {
-    canvas = document.createElement("canvas");
-    canvas.width = 100;
-    canvas.height = 20;
-    ctx = canvas.getContext("2d")!;
-  });
-
-  it("should initialize and draw the background", () => {
-    const spyClearRect = vi.spyOn(ctx, "clearRect");
-    const spyFillRect = vi.spyOn(ctx, "fillRect");
-    const spyFillStyle = vi.spyOn(ctx, "fillStyle", "set");
-    const bar = new ProgressBar(["#ff0000", "#00ff00"], ctx, 2, 2, 80, 10, 0.5);
-    expect(spyClearRect).toHaveBeenCalledWith(0, 0, 82, 12);
-    expect(spyFillRect).toHaveBeenCalledWith(1, 1, 80, 10);
-    expect(spyFillStyle).toHaveBeenCalledWith("#00ff00");
-    expect(bar.getX()).toBe(2);
-    expect(bar.getY()).toBe(2);
-  });
-
-  it("should set progress and draw the progress bar", () => {
-    const bar = new ProgressBar(["#ff0000", "#00ff00"], ctx, 2, 2, 80, 10);
-    const spyFillRect = vi.spyOn(ctx, "fillRect");
-    bar.setProgress(0.5);
-    expect(bar.getProgress()).toBe(0.5);
-    expect(spyFillRect).toHaveBeenCalledWith(
-      2,
-      2,
-      Math.floor(0.5 * (80 - 2)),
-      8,
-    );
-    expect(ctx.fillStyle).toBe("#00ff00");
-
-    bar.setProgress(0.1);
-    expect(ctx.fillStyle).toBe("#ff0000");
-  });
-
-  it("should clamp progress between 0 and 1 on init", () => {
-    const bar = new ProgressBar(["#ff0000", "#00ff00"], ctx, 2, 2, 80, 10, -1);
-    expect(bar.getProgress()).toBe(0);
-    const bar2 = new ProgressBar(["#ff0000", "#00ff00"], ctx, 2, 2, 80, 10, 2);
-    expect(bar2.getProgress()).toBe(1);
-  });
-
-  it("should handle empty colors array gracefully", () => {
-    const bar = new ProgressBar([], ctx, 2, 2, 80, 10, 0.5);
-    expect(() => bar.setProgress(0.5)).not.toThrow();
-    expect(ctx.fillStyle).toBe("#808080");
-  });
-});