feat: v1.29.0 — Radio fast-start, seek fix, OGG, error toasts, contributors

Incorporates PRs #38 (nisarg-78), #42 #43 #44 (JulianNymark) with fixes:

Audio / Playback
- Artist Radio starts immediately from fast getTopSongs (local library);
  getSimilarSongs2 (Last.fm) enriches queue in background — no more wait
- Fix seek audio glitch: EqualPowerFadeIn only resets to zero-gain on
  seeks to track start (<100 ms); all other seeks resume at unity gain
- OGG/Vorbis container support via symphonia-format-ogg (PR #42)
- Human-readable audio error messages in SizedDecoder (PR #44)
- Audio playback errors shown as themed toast notifications (PR #43)

Queue / Radio
- Infinite Queue: proactive load of 5 tracks (was 25) when ≤2 remain
- Radio: proactive reload at ≤2 remaining tracks, independent of
  Infinite Queue setting — radio no longer stops at last track
- Fix: clicking Start Radio multiple times no longer stacks duplicates
- Fix: Start Radio on artist keeps current song playing
- Manual tracks always appear before Radio, Radio before Auto-added
- Queue separators: "— Radio —" and "— Auto —" dividers
- Fix: radio proactive load now works even when songs lack artistId
  (uses currentRadioArtistId module var as fallback)

UI / UX
- Click synced lyrics lines to seek (PR #38)
- Volume scroll wheel on volume slider (PR #38)
- Lyrics: active / completed / upcoming visual states (PR #38)
- Shared toast utility (src/utils/toast.ts) replaces inline toast fn
- Auto-updater: relaunch_after_update Rust command exits first to
  release single-instance lock before spawning new process

About / Credits
- nisarg-78 and JulianNymark added to contributors (since v1.29.0)
- netherguy4 added as Special Thanks for feature ideas and feedback
- i18n: aboutSpecialThanksLabel in all 5 languages

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

src/App.tsx

@@ -1,4 +1,5 @@
 import React, { useEffect, useState, useCallback, useRef } from 'react';
+import { showToast } from './utils/toast';
 import { BrowserRouter, Routes, Route, Navigate, useNavigate, useLocation } from 'react-router-dom';
 import { listen } from '@tauri-apps/api/event';
 import { invoke } from '@tauri-apps/api/core';
@@ -433,20 +434,6 @@ export default function App() {
 
   const handleExport = async (since: number) => {
     setExportPickerOpen(false);
-    const showToast = (text: string) => {
-      const toast = document.createElement('div');
-      toast.textContent = text;
-      toast.style.cssText = `
-        position:fixed; bottom:100px; left:50%; transform:translateX(-50%);
-        background:#24273a; color:#cad3f5; border:1px solid #363a4f;
-        padding:10px 20px; border-radius:10px; font-size:14px;
-        z-index:999999; pointer-events:none;
-        box-shadow:0 4px 24px rgba(0,0,0,0.5);
-        white-space:nowrap;
-      `;
-      document.body.appendChild(toast);
-      setTimeout(() => toast.remove(), 4000);
-    };
     try {
       const { exportNewAlbumsImage } = await import('./utils/exportNewAlbums');
       const result = await exportNewAlbumsImage(since);