fix(pwa/security): add manifest id, noreferrer to target=_blank

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

index.html

@@ -968,7 +968,7 @@
             <button class="btn-secondary" id="sheetBrainBtn">
                 <i data-lucide="bookmark"></i> Brainに保存
             </button>
-            <a class="btn-primary" id="sheetLinkBtn" href="#" target="_blank" rel="noopener">
+            <a class="btn-primary" id="sheetLinkBtn" href="#" target="_blank" rel="noopener noreferrer">
                 <i data-lucide="external-link"></i> 詳細を見る
             </a>
         </div>
@@ -1118,7 +1118,7 @@
                 <button class="action-btn ${saved ? 'saved' : ''}" title="Brainに保存" onclick="saveToBrain('${ev.id}',event)">
                     <i data-lucide="${saved ? 'bookmark-check' : 'bookmark'}"></i>
                 </button>
-                <a class="action-btn" href="${escapeHTML(ev.url)}" target="_blank" rel="noopener" title="詳細を見る">
+                <a class="action-btn" href="${escapeHTML(ev.url)}" target="_blank" rel="noopener noreferrer" title="詳細を見る">
                     <i data-lucide="external-link"></i>
                 </a>
             </div>
@@ -1252,7 +1252,7 @@
         <div class="sheet-meta-row"><i data-lucide="calendar"></i><span>${formatDateRange(ev)}</span></div>
         <div class="sheet-meta-row"><i data-lucide="map-pin"></i>
             <span><a href="https://www.google.com/maps/search/?api=1&query=${encodeURIComponent(ev.location + ' ' + ev.address)}"
-               target="_blank" rel="noopener" style="color:var(--accent);text-decoration:none;">${escapeHTML(ev.location)}</a></span>
+               target="_blank" rel="noopener noreferrer" style="color:var(--accent);text-decoration:none;">${escapeHTML(ev.location)}</a></span>
         </div>
         <div class="sheet-meta-row"><i data-lucide="info"></i>
             <span style="color:var(--text3);font-size:12px;">情報元: ${escapeHTML(ev.source)}</span></div>`;

manifest.json

@@ -1,4 +1,5 @@
 {
+  "id": "/posimai-tech-events/",
   "name": "Posimai Tech",
   "short_name": "Tech Events",
   "description": "ITイベント・Connpass検索アプリ",