feat(icons): render the app icons from the Movie Loop mark

Safari, the iOS home screen, Android install and push notifications
still showed the old film-reel artwork beside the new theme colour. The
PNGs are now rendered from the SVG mark by `npm run icons` (Inkscape,
no image library in node_modules): the bare mark for the 32px favicon,
the mark on the stage colour for app icons, and a maskable variant with
the extra margin Android's adaptive crop needs.

scripts/make-icons.test.ts

@@ -0,0 +1,96 @@
+import { existsSync } from 'node:fs';
+import { resolve } from 'node:path';
+import { describe, expect, it, vi } from 'vitest';
+import {
+  ICONS,
+  INKSCAPE_CANDIDATES,
+  exportArgs,
+  findInkscape,
+  makeIcons,
+} from './make-icons.mjs';
+
+/**
+ * The PNG icons are rendered from SVG by Inkscape rather than checked in by
+ * hand, so the manifest, the service worker and the HTML can keep pointing at
+ * the same filenames while the mark changes. These tests pin the plan (which
+ * file comes from which source, at what size) and the Inkscape invocation;
+ * they never run Inkscape.
+ */
+
+const ROOT = resolve(__dirname, '..');
+
+describe('ICONS', () => {
+  it('covers every raster icon the app references, from a source that exists', () => {
+    const outs = ICONS.map((i) => i.out);
+    expect(outs).toEqual(
+      expect.arrayContaining([
+        'public/favicon-32.png',
+        'public/apple-touch-icon.png',
+        'public/icon-192.png',
+        'public/icon-512.png',
+        'public/icon-512-maskable.png',
+      ]),
+    );
+    for (const icon of ICONS) {
+      expect(existsSync(resolve(ROOT, icon.source)), icon.source).toBe(true);
+    }
+  });
+
+  it('renders the tab favicon from the bare mark and the app icons from the opaque source', () => {
+    const favicon = ICONS.find((i) => i.out === 'public/favicon-32.png');
+    expect(favicon?.source).toBe('public/favicon.svg');
+    expect(favicon?.size).toBe(32);
+    for (const out of ['public/apple-touch-icon.png', 'public/icon-192.png', 'public/icon-512.png']) {
+      expect(ICONS.find((i) => i.out === out)?.source).toBe('scripts/icons/app-icon.svg');
+    }
+    expect(ICONS.find((i) => i.out === 'public/icon-512-maskable.png')?.source).toBe(
+      'scripts/icons/app-icon-maskable.svg',
+    );
+  });
+});
+
+describe('findInkscape', () => {
+  it('prefers an explicit INKSCAPE variable', () => {
+    expect(findInkscape({ INKSCAPE: 'D:\\tools\\inkscape.com' }, () => true)).toBe(
+      'D:\\tools\\inkscape.com',
+    );
+  });
+
+  it('falls back to the first standard install location that exists', () => {
+    const second = INKSCAPE_CANDIDATES[1]!;
+    expect(findInkscape({}, (p: string) => p === second)).toBe(second);
+  });
+
+  it('falls back to PATH lookup when nothing is installed in a standard place', () => {
+    expect(findInkscape({}, () => false)).toBe('inkscape');
+  });
+});
+
+describe('exportArgs', () => {
+  it('builds an Inkscape 1.x PNG export at the requested square size', () => {
+    expect(exportArgs({ source: 'in.svg', out: 'out.png', size: 180 })).toEqual([
+      'in.svg',
+      '--export-type=png',
+      '--export-filename=out.png',
+      '--export-width=180',
+      '--export-height=180',
+    ]);
+  });
+});
+
+describe('makeIcons', () => {
+  it('runs one export per icon, with paths resolved against the project root', () => {
+    const run = vi.fn();
+    const log = vi.spyOn(console, 'log').mockImplementation(() => {});
+    try {
+      makeIcons(ROOT, run);
+    } finally {
+      log.mockRestore();
+    }
+    expect(run).toHaveBeenCalledTimes(ICONS.length);
+    const [, args, opts] = run.mock.calls[0]!;
+    expect(args[0]).toBe(resolve(ROOT, ICONS[0]!.source));
+    expect(args).toContain(`--export-filename=${resolve(ROOT, ICONS[0]!.out)}`);
+    expect(opts).toEqual({ stdio: 'inherit' });
+  });
+});