peek panels: reusable editor module — shared _page_editor_content.html + embed template

Architecture for zero code duplication:
- Extract page editor HTML into _page_editor_content.html (shared include)
- page_editor.html includes it (same behavior as before)
- page_editor_embed.html includes it with empty topbar (no header in peek)
- board.py: ?embed=1 renders page_editor_embed.html

Peek panels now load /pages/{id}?embed=1 in iframe:
- Editor renders without sidebar or header breadcrumb/actions
- Full editing capability (blocks, markdown, slash commands, save)
- Same code — one change to _page_editor_content.html updates everywhere

app/templates/local_workspace.html

@@ -831,20 +831,16 @@ window._wsInitData = (function() {
       return null;
     },
 
-    // ── Preview panel (vanilla JS — matches Library peek-overlay) ──
+    // ── Preview panel (loads editor in iframe via /pages/{id}?embed=1) ──
     selectForPreview(node) {
       var panel = document.getElementById('ws-preview-panel');
       if (!panel) return;
-      // Icon + title
       document.getElementById('ws-preview-icon').innerHTML = this._fileIcon(node.name, node.is_folder, node.content_format);
       document.getElementById('ws-preview-title').textContent = node.name;
-      // Open button → navigate to /pages/{id}
       var openBtn = document.getElementById('ws-preview-open-btn');
       openBtn.onclick = function() { window.location = '/pages/' + node.id; };
-      // Favorite button
       var favBtn = document.getElementById('ws-preview-fav-btn');
       favBtn.onclick = function() { window.showToast('Favorite toggled', 'success'); };
-      // Copy link button
       var copyBtn = document.getElementById('ws-preview-copy-btn');
       copyBtn.onclick = function() {
         var url = window.location.origin + '/pages/' + node.id;
@@ -854,30 +850,16 @@ window._wsInitData = (function() {
           window.showToast('Failed to copy', 'error');
         });
       };
-      // Body: meta info header + loading indicator
-      var meta = '<div style="display:flex;gap:16px;flex-wrap:wrap;padding-bottom:12px;margin-bottom:12px;border-bottom:1px solid var(--border);font-size:12px;color:var(--text-tertiary);">'
-        + '<span>' + (node.is_folder ? 'Folder' : this._fileTypeLabel(node.name, node.content_format)) + '</span>'
-        + '<span>' + (node.size_display || '-') + '</span>'
-        + '<span>' + this._formatDate(node.updated_at) + '</span>'
-        + '</div>';
-      if (node.tags && node.tags.length > 0) {
-        meta += '<div style="display:flex;gap:4px;flex-wrap:wrap;margin-bottom:12px;">';
-        for (var i = 0; i < node.tags.length; i++) {
-          var t = node.tags[i];
-          meta += '<span class="tag-chip" style="background:' + this._escHtml(t.color) + '">' + this._escHtml(t.name) + '</span>';
-        }
-        meta += '</div>';
-      }
-      document.getElementById('ws-preview-body').innerHTML = meta + '<div style="text-align:center;padding:40px;color:var(--text-tertiary)">Loading...</div>';
-      // Show panel with slide-in
+      // Load editor in iframe
+      var iframe = document.getElementById('ws-preview-iframe');
+      if (iframe) iframe.src = '/pages/' + node.id + '?embed=1';
+      // Show panel
       panel.style.display = 'flex';
       requestAnimationFrame(function() {
         requestAnimationFrame(function() {
           panel.style.transform = 'translateX(0)';
         });
       });
-      // Load content async
-      this._loadPreviewContentVanilla(node);
     },
 
     closePreviewPanel() {
@@ -2949,9 +2931,7 @@ console.log('FLOWDECK v2.4.6 — IIFE done, _wsInitData keys:', Object.keys(wind
         </div>
       </div>
     </div>
-    <div id="ws-preview-body" style="flex:1;overflow-y:auto;padding:16px 20px;">
-      <div style="text-align:center;padding:60px 20px;color:var(--text-dim);">{{ fd_icon("file",32) }}<div style="margin-top:8px;font-size:14px;">Select a file to preview</div></div>
-    </div>
+    <iframe id="ws-preview-iframe" src="" style="width:100%;height:100%;border:none;flex:1;"></iframe>
   </div>
 </div><!-- /ws-split -->