refactor: update branding assets and convert settings to accordion UI

- Replace SVG favicons with PNG icons from new smeshicon assets
- Add theme-aware Icon component using smeshiconlight/dark PNGs
- Refactor Settings page to use collapsible accordion sections
- Add Radix UI accordion component with animations
- Update QrCode component to use new PNG icon
- Remove old favicon.svg and nostr.json files
- Add new logo assets in resources/ and src/assets/

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

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

package.json

@@ -26,6 +26,7 @@
     "@dnd-kit/utilities": "^3.2.2",
     "@getalby/bitcoin-connect-react": "^3.10.0",
     "@noble/hashes": "^1.6.1",
+    "@radix-ui/react-accordion": "^1.2.12",
     "@radix-ui/react-alert-dialog": "^1.1.4",
     "@radix-ui/react-avatar": "^1.1.2",
     "@radix-ui/react-checkbox": "^1.3.3",