Add TradingView chart widget + MIDI/tab close fixes

- investor skill: TradingView 실시간 주가 차트 렌더링 지원
  - ```tradingview SYMBOL|INTERVAL``` 블록 → 차트 위젯 자동 생성
  - JSON 형식 출력 시 HTML 언이스케이프 후 파싱 (symbol/interval 추출)
  - renderTVChart(): tv.js 동적 로드, 다크/라이트 테마 연동, RSI·MACD 기본 포함
- musician skill: MIDI 다운로드 사이트 4개 추가 (freemidi, bitmidi, piano-midi, midiworld)
- MIDI 탭 닫기 버그: window.open에 noopener,noreferrer 추가
- beforeunload/pagehide 시 midiRouter.stop() 호출

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

web-ui/index.html

@@ -9253,6 +9253,37 @@ function renderMarkdown(text, opts) {
         '</div>' +
       '</div>';
     }
+    if (lang === 'tradingview') {
+      var tvSymbol = '', tvInterval = 'D';
+      // code content is already HTML-escaped at this point — unescape before parsing
+      var tvRaw = trimmed.replace(/&amp;/g,'&').replace(/&lt;/g,'<').replace(/&gt;/g,'>').replace(/&quot;/gi,'"').replace(/&#39;/g,"'").trim();
+      if (tvRaw.startsWith('{')) {
+        try {
+          var tvJson = JSON.parse(tvRaw);
+          tvSymbol = (tvJson.symbol || tvJson.SYMBOL || '').toString().toUpperCase();
+          tvInterval = (tvJson.interval || tvJson.INTERVAL || 'D').toString().toUpperCase();
+        } catch(e) { tvSymbol = tvRaw.split('|')[0].trim().toUpperCase(); }
+      } else {
+        var parts = tvRaw.split('|');
+        tvSymbol = (parts[0] || '').trim().toUpperCase();
+        tvInterval = (parts[1] || 'D').trim().toUpperCase();
+      }
+      if (!tvSymbol) return '<pre class="md-code-block"><code>' + trimmed + '</code></pre>';
+      var tvId = 'tv-' + Math.random().toString(36).slice(2, 9);
+      return '<div class="music-widget" id="' + tvId + '">' +
+        '<div class="music-widget-header">' +
+          '<span class="music-widget-label">📈 ' + escHtml(tvSymbol) + ' · ' + escHtml(tvInterval) + '</span>' +
+          '<div style="display:flex;gap:6px;align-items:center">' +
+            '<button class="music-render-btn" onclick="renderTVChart(this,\'' + tvId + '-c\',\'' + escHtml(tvSymbol) + '\',\'' + escHtml(tvInterval) + '\')">📈 차트 불러오기</button>' +
+            '<button onclick="toggleMusicWidget(\'' + tvId + '\')" style="background:none;border:none;cursor:pointer;font-size:14px;color:var(--muted);padding:2px 4px" title="접기/펼치기">▾</button>' +
+            '<button onclick="closeMusicWidget(\'' + tvId + '\')" style="background:none;border:none;cursor:pointer;font-size:14px;color:var(--muted);padding:2px 4px" title="닫기">✕</button>' +
+          '</div>' +
+        '</div>' +
+        '<div class="music-widget-body">' +
+          '<div id="' + tvId + '-c" style="height:440px;width:100%"></div>' +
+        '</div>' +
+      '</div>';
+    }
     return '<pre class="md-code-block"><code>' + trimmed + '</code></pre>';
   });
 
@@ -9286,6 +9317,45 @@ function renderMarkdown(text, opts) {
   return html;
 }
 
+function renderTVChart(btn, containerId, symbol, interval) {
+  btn.disabled = true;
+  btn.textContent = '로딩 중...';
+  var isDark = document.documentElement.getAttribute('data-theme') !== 'light';
+  function doInit() {
+    try {
+      new TradingView.widget({
+        container_id: containerId,
+        autosize: true,
+        symbol: symbol,
+        interval: interval || 'D',
+        timezone: 'Asia/Seoul',
+        theme: isDark ? 'dark' : 'light',
+        style: '1',
+        locale: 'kr',
+        enable_publishing: false,
+        allow_symbol_change: true,
+        save_image: false,
+        withdateranges: true,
+        hide_side_toolbar: false,
+        studies: ['RSI@tv-basicstudies', 'MACD@tv-basicstudies'],
+      });
+      btn.style.display = 'none';
+    } catch(e) {
+      btn.disabled = false;
+      btn.textContent = '📈 차트 불러오기';
+    }
+  }
+  if (window.TradingView && window.TradingView.widget) {
+    doInit();
+  } else {
+    var s = document.createElement('script');
+    s.src = 'https://s3.tradingview.com/tv.js';
+    s.onload = doInit;
+    s.onerror = function() { btn.disabled = false; btn.textContent = '📈 차트 불러오기'; };
+    document.head.appendChild(s);
+  }
+}
+
 function toggleMusicWidget(widgetId) {
   var widget = document.getElementById(widgetId);
   if (!widget) return;
@@ -9495,7 +9565,7 @@ function buildMusicActions(data, downloadName) {
       + '<span style="font-size:11px;color:var(--muted)" id="' + rid + '-st"></span>'
       + '</div>';
     html += '<button class="music-dl-btn btn-green"  id="' + rid + '-btn" onclick="midiRouterToggle(\'' + rid + '\',\'' + rid + '-btn\')">▶ 외부 신디</button>';
-    html += '<button class="music-dl-btn btn-purple" onclick="window.open(\'/midi-editor.html?url=\'+encodeURIComponent(\'' + midiUrl + '\'),\'_blank\')">🎹 편집</button>';
+    html += '<button class="music-dl-btn btn-purple" onclick="window.open(\'/midi-editor.html?url=\'+encodeURIComponent(\'' + midiUrl + '\'),\'_blank\',\'noopener,noreferrer\')">🎹 편집</button>';
     html += '<a class="music-dl-btn" href="' + midiUrl + '" download="' + escHtml(downloadName || 'score.midi') + '">⬇ MIDI</a>';
   }
   if (pdfUrl) html += '<a class="music-dl-btn" href="' + pdfUrl + '" download="score.pdf">⬇ PDF</a>';
@@ -9616,7 +9686,7 @@ function buildMidiPickerWidget(data, filename) {
         savedLine +
         '<div style="display:flex;gap:8px;flex-wrap:wrap;align-items:center">' +
           '<button class="music-dl-btn btn-green"  onclick="midiRouterToggle(\'' + rid + '\',\'' + rid + '\')">▶ 재생</button>' +
-          '<button class="music-dl-btn btn-purple" onclick="window.open(\'/midi-editor.html?url=\'+encodeURIComponent(\'' + midiUrl + '\'),\'_blank\')">🎹 편집</button>' +
+          '<button class="music-dl-btn btn-purple" onclick="window.open(\'/midi-editor.html?url=\'+encodeURIComponent(\'' + midiUrl + '\'),\'_blank\',\'noopener,noreferrer\')">🎹 편집</button>' +
           '<button class="music-dl-btn btn-amber"  id="' + wid + '-score-btn" onclick="midiPickerScore(\'' + wid + '\',\'' + data.id + '\',\'' + escHtml(filename) + '\')">' + scoreBtnLabel + '</button>' +
         '</div>' +
         playerPanel +
@@ -11061,6 +11131,10 @@ function canvasRun() {
   });
 })();
 
+// Stop MIDI playback when tab is closed or navigated away
+window.addEventListener('beforeunload', () => { try { midiRouter.stop(); } catch {} });
+window.addEventListener('pagehide', () => { try { midiRouter.stop(); } catch {} });
+
 // Resize xterm when window resizes
 window.addEventListener('resize', () => {
   const shell = getActiveShell();