feat: Improve UI layout and navigation

- Increase logo size (48x48 desktop, 56x56 mobile) for better visibility
- Add logo as favicon
- Add logo to mobile header
- Move user menu to navigation bars (sidebar on desktop, bottom bar on mobile)
- Fix desktop chat layout - container structure prevents voice controls cutoff
- Fix mobile bottom bar - use icon-only ActionIcons instead of truncated text buttons
- Hide Create Node/New Conversation buttons on mobile to save header space
- Make fixed header and voice controls work properly with containers

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

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

lib/auth/oauth-client.ts

@@ -38,9 +38,10 @@ export async function getOAuthClient(): Promise<NodeOAuthClient> {
   if (isDev) {
     // Development: Use localhost loopback client
     // Per ATproto spec, we encode metadata in the client_id query params
+    // Request 'transition:generic' scope for repository write access
     const clientId = `http://localhost/?${new URLSearchParams({
       redirect_uri: callbackUrl,
-      scope: 'atproto',
+      scope: 'atproto transition:generic',
     }).toString()}`;
 
     console.log('[OAuth] Initializing development client with loopback exception');
@@ -50,7 +51,7 @@ export async function getOAuthClient(): Promise<NodeOAuthClient> {
       clientMetadata: {
         client_id: clientId,
         redirect_uris: [callbackUrl],
-        scope: 'atproto',
+        scope: 'atproto transition:generic',
         grant_types: ['authorization_code', 'refresh_token'],
         response_types: ['code'],
         application_type: 'native',