feat: complete Phase 2 network features for spellbooks

Sharing Enhancements:
- Install qrcode library for QR code generation
- Create ShareSpellbookDialog with tabbed interface
- Support multiple share formats: Web URL, naddr, nevent
- QR code generation and download for each format
- Quick copy buttons with visual feedback
- Integrated into SpellbookDetailRenderer

Network Discovery:
- Add "Discover" filter to browse spellbooks from other users
- Query AGGREGATOR_RELAYS for network spellbook discovery
- Show author names using UserName component
- Conditional UI: hide owner actions for discovered spellbooks
- Support viewing and applying layouts from the community

Preview Route Polish:
- Loading states with spinner during NIP-05 resolution
- 10-second timeout for NIP-05 resolution
- Error banners for resolution failures
- Author name and creation date in preview banner
- Copy link button in preview mode

Conflict Resolution:
- compareSpellbookVersions() function in spellbook-manager
- ConflictResolutionDialog component for version conflicts
- Side-by-side comparison of local vs network versions
- Show workspace/window counts and timestamps

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package.json

@@ -30,6 +30,7 @@
     "@radix-ui/react-slot": "^1.2.4",
     "@radix-ui/react-tabs": "^1.1.13",
     "@radix-ui/react-tooltip": "^1.2.8",
+    "@types/qrcode": "^1.5.6",
     "applesauce-accounts": "^4.1.0",
     "applesauce-actions": "^4.0.0",
     "applesauce-content": "^4.0.0",
@@ -38,7 +39,6 @@
     "applesauce-react": "^4.0.0",
     "applesauce-relay": "latest",
     "applesauce-signers": "^4.1.0",
-    "applesauce-vault": "^4.1.0",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
     "cmdk": "^1.1.1",
@@ -53,6 +53,7 @@
     "lucide-react": "latest",
     "media-chrome": "^4.17.2",
     "prismjs": "^1.30.0",
+    "qrcode": "^1.5.4",
     "react": "^19.2.1",
     "react-dom": "^19.2.1",
     "react-markdown": "^10.1.0",