feat: Waveform seekbar, MilkDrop visualizer, EQ bars, in-app browser, and UX improvements (v1.3.0)

- PlayerBar redesigned: canvas waveform seekbar (500 bars, blue→mauve gradient + glow) replaces thin slider; new flex layout; queue toggle moved to content header (consistent with sidebar pattern)
- MilkDrop visualizer in Ambient Stage via Butterchurn; hidden audio analysis, preset shuffle, smooth blend transitions
- Tracklist: animated EQ bars for playing track, play icon when paused, align-items: center fix
- Artist pages: Last.fm + Wikipedia open in native Tauri WebviewWindow (in-app browser)
- Hero/Discover deduplication: single fetch of 20 random albums split between sections
- Update checker: runs every 10 minutes during runtime; version shown without v-prefix
- Settings version: now read from package.json instead of hardcoded
- Help page: new Random Mix section, updated Playback + Library sections, improved accordion styling
- Bump version to 1.3.0

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/WaveformSeek.tsx

@@ -0,0 +1,180 @@
+import React, { useEffect, useRef } from 'react';
+import { usePlayerStore } from '../store/playerStore';
+
+const BAR_COUNT = 500;
+
+function hashStr(str: string): number {
+  let h = 0x811c9dc5;
+  for (let i = 0; i < str.length; i++) {
+    h = (h ^ str.charCodeAt(i)) >>> 0;
+    h = Math.imul(h, 0x01000193) >>> 0;
+  }
+  return h;
+}
+
+function makeHeights(trackId: string): Float32Array {
+  let s = hashStr(trackId);
+  const h = new Float32Array(BAR_COUNT);
+  for (let i = 0; i < BAR_COUNT; i++) {
+    s = (Math.imul(s, 1664525) + 1013904223) >>> 0;
+    h[i] = s / 0xffffffff;
+  }
+  // Smooth for an organic look
+  for (let pass = 0; pass < 5; pass++) {
+    for (let i = 1; i < BAR_COUNT - 1; i++) {
+      h[i] = h[i - 1] * 0.25 + h[i] * 0.5 + h[i + 1] * 0.25;
+    }
+  }
+  // Normalize to [0.12, 1.0]
+  let max = 0;
+  for (let i = 0; i < BAR_COUNT; i++) if (h[i] > max) max = h[i];
+  if (max > 0) {
+    for (let i = 0; i < BAR_COUNT; i++) h[i] = 0.12 + (h[i] / max) * 0.88;
+  }
+  return h;
+}
+
+function drawWaveform(
+  canvas: HTMLCanvasElement,
+  heights: Float32Array | null,
+  progress: number,
+  buffered: number,
+) {
+  const ctx = canvas.getContext('2d');
+  if (!ctx) return;
+
+  const rect = canvas.getBoundingClientRect();
+  const w = rect.width || canvas.clientWidth;
+  const h = rect.height || canvas.clientHeight;
+  if (w === 0 || h === 0) return;
+
+  const dpr = window.devicePixelRatio || 1;
+  const pw = Math.round(w * dpr);
+  const ph = Math.round(h * dpr);
+  if (canvas.width !== pw || canvas.height !== ph) {
+    canvas.width = pw;
+    canvas.height = ph;
+  }
+  ctx.setTransform(dpr, 0, 0, dpr, 0, 0);
+  ctx.clearRect(0, 0, w, h);
+
+  const style = getComputedStyle(document.documentElement);
+  const colorBlue     = style.getPropertyValue('--ctp-blue').trim()     || '#89b4fa';
+  const colorMauve    = style.getPropertyValue('--ctp-mauve').trim()    || '#cba6f7';
+  const colorBuffered = style.getPropertyValue('--ctp-overlay0').trim() || '#6c7086';
+  const colorUnplayed = style.getPropertyValue('--ctp-surface1').trim() || '#313244';
+
+  if (!heights) {
+    ctx.globalAlpha = 0.3;
+    ctx.fillStyle = colorUnplayed;
+    ctx.fillRect(0, (h - 2) / 2, w, 2);
+    ctx.globalAlpha = 1;
+    return;
+  }
+
+  // Use fractional x positions so adjacent bars share exact pixel boundaries — no gaps.
+  const x1Of = (i: number) => (i / BAR_COUNT) * w;
+  const x2Of = (i: number) => ((i + 1) / BAR_COUNT) * w;
+
+  // Pass 1 — unplayed (dim)
+  ctx.globalAlpha = 0.28;
+  ctx.fillStyle = colorUnplayed;
+  for (let i = 0; i < BAR_COUNT; i++) {
+    if (i / BAR_COUNT < buffered) continue;
+    const barH = Math.max(1, heights[i] * h);
+    const x = x1Of(i);
+    ctx.fillRect(x, (h - barH) / 2, x2Of(i) - x, barH);
+  }
+
+  // Pass 2 — buffered (slightly brighter)
+  ctx.globalAlpha = 0.45;
+  ctx.fillStyle = colorBuffered;
+  for (let i = 0; i < BAR_COUNT; i++) {
+    const frac = i / BAR_COUNT;
+    if (frac < progress || frac >= buffered) continue;
+    const barH = Math.max(1, heights[i] * h);
+    const x = x1Of(i);
+    ctx.fillRect(x, (h - barH) / 2, x2Of(i) - x, barH);
+  }
+
+  // Pass 3 — played (gradient + glow)
+  if (progress > 0) {
+    const grad = ctx.createLinearGradient(0, 0, progress * w, 0);
+    grad.addColorStop(0, colorBlue);
+    grad.addColorStop(1, colorMauve);
+    ctx.globalAlpha = 1;
+    ctx.fillStyle = grad;
+    ctx.shadowColor = colorMauve;
+    ctx.shadowBlur = 5;
+    for (let i = 0; i < BAR_COUNT; i++) {
+      if (i / BAR_COUNT >= progress) break;
+      const barH = Math.max(1, heights[i] * h);
+      const x = x1Of(i);
+      ctx.fillRect(x, (h - barH) / 2, x2Of(i) - x, barH);
+    }
+    ctx.shadowBlur = 0;
+  }
+
+  ctx.globalAlpha = 1;
+}
+
+interface Props {
+  trackId: string | undefined;
+}
+
+export default function WaveformSeek({ trackId }: Props) {
+  const canvasRef   = useRef<HTMLCanvasElement>(null);
+  const heightsRef  = useRef<Float32Array | null>(null);
+  const progressRef = useRef(0);
+  const bufferedRef = useRef(0);
+  const isDragging  = useRef(false);
+
+  const progress = usePlayerStore(s => s.progress);
+  const buffered = usePlayerStore(s => s.buffered);
+  const seek     = usePlayerStore(s => s.seek);
+
+  progressRef.current = progress;
+  bufferedRef.current = buffered;
+
+  useEffect(() => {
+    heightsRef.current = trackId ? makeHeights(trackId) : null;
+  }, [trackId]);
+
+  useEffect(() => {
+    if (canvasRef.current) {
+      drawWaveform(canvasRef.current, heightsRef.current, progress, buffered);
+    }
+  }, [progress, buffered, trackId]);
+
+  useEffect(() => {
+    const canvas = canvasRef.current;
+    if (!canvas) return;
+    const ro = new ResizeObserver(() => {
+      drawWaveform(canvas, heightsRef.current, progressRef.current, bufferedRef.current);
+    });
+    ro.observe(canvas);
+    return () => ro.disconnect();
+  }, []);
+
+  const seekFromX = (clientX: number) => {
+    const canvas = canvasRef.current;
+    if (!canvas || !trackId) return;
+    const rect = canvas.getBoundingClientRect();
+    seek(Math.max(0, Math.min(1, (clientX - rect.left) / rect.width)));
+  };
+
+  useEffect(() => {
+    const up = () => { isDragging.current = false; };
+    window.addEventListener('mouseup', up);
+    return () => window.removeEventListener('mouseup', up);
+  }, []);
+
+  return (
+    <canvas
+      ref={canvasRef}
+      style={{ width: '100%', height: '24px', cursor: trackId ? 'pointer' : 'default', display: 'block' }}
+      onMouseDown={e => { isDragging.current = true; seekFromX(e.clientX); }}
+      onMouseMove={e => { if (isDragging.current) seekFromX(e.clientX); }}
+    />
+  );
+}