Visualizer: add the classic iTunes-style swirl and make it the music default

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UaC9HmtHMdRP8dAbN4wAKj

tools/visualizer-test.js

@@ -7,7 +7,7 @@ const ctx = { window: {}, document: { createElement: () => ({ getContext: () =>
 vm.createContext(ctx); vm.runInContext(src + '\nthis.vizKind = vizKind; this.VIZ_MODES = VIZ_MODES;', ctx);
 for (const k of ['pod:1', 'ab:2', 'lv:3', 'vbv:4']) ok(ctx.vizKind({ key: k }) === 'speech', k + ' is speech');
 for (const k of ['12345', 'radio:journeyfm']) ok(ctx.vizKind({ key: k }) === 'music', k + ' is music');
-ok(ctx.VIZ_MODES.length === 5, 'five looks');
+ok(ctx.VIZ_MODES.length === 6 && ctx.VIZ_MODES[0][0] === 'classic', 'six looks, Classic first');
 const root = __dirname + '/../public/', rd = f => fs.readFileSync(root + f, 'utf8');
 ok(rd('index.html').includes('/visualizer.js'), 'script is loaded');
 ok(rd('player.js').includes("id=\"npv\"") && rd('player.js').includes("id=\"cnv\""), 'buttons in the player and the Music card');