debug: add logging to bookmark grouping to diagnose missing bookmarks

Added console logs to groupIndividualBookmarks to see:
- Total items being grouped
- Count per group (nip51Public, nip51Private, amethystPublic, amethystPrivate, standaloneWeb)
- Sample of first 3 items with their sourceKind and isPrivate properties

This will help diagnose why 532 bookmarks are emitted but not appearing in sidebar.

src/utils/bookmarkUtils.tsx

@@ -93,6 +93,8 @@ export const sortIndividualBookmarks = (items: IndividualBookmark[]) => {
 export function groupIndividualBookmarks(items: IndividualBookmark[]) {
   const sorted = sortIndividualBookmarks(items)
   
+  console.log('[bookmark] 🗂️ Grouping', sorted.length, 'items')
+  
   // Group by source list, not by content type
   const nip51Public = sorted.filter(i => i.sourceKind === 10003 && !i.isPrivate)
   const nip51Private = sorted.filter(i => i.sourceKind === 10003 && i.isPrivate)
@@ -100,6 +102,23 @@ export function groupIndividualBookmarks(items: IndividualBookmark[]) {
   const amethystPrivate = sorted.filter(i => i.sourceKind === 30001 && i.isPrivate)
   const standaloneWeb = sorted.filter(i => i.sourceKind === 39701)
   
+  console.log('[bookmark] 🗂️ Groups:', {
+    nip51Public: nip51Public.length,
+    nip51Private: nip51Private.length,
+    amethystPublic: amethystPublic.length,
+    amethystPrivate: amethystPrivate.length,
+    standaloneWeb: standaloneWeb.length
+  })
+  
+  // Debug: sample first few items to see their properties
+  if (sorted.length > 0) {
+    console.log('[bookmark] 🗂️ Sample items:', sorted.slice(0, 3).map(i => ({
+      sourceKind: i.sourceKind,
+      isPrivate: i.isPrivate,
+      id: i.id.slice(0, 16)
+    })))
+  }
+  
   return { 
     nip51Public, 
     nip51Private,