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>

index.html

@@ -13,7 +13,7 @@
 
     <meta name="apple-mobile-web-app-title" content="Smesh" />
     <link rel="icon" href="/favicon.ico" sizes="48x48" />
-    <link rel="icon" href="/favicon.svg" sizes="any" type="image/svg+xml" />
+    <link rel="icon" href="/favicon.png" sizes="256x256" type="image/png" />
     <meta name="theme-color" content="#171717" media="(prefers-color-scheme: dark)" />
     <meta name="theme-color" content="#FFFFFF" media="(prefers-color-scheme: light)" />