Tighten title bar icon-to-text gap from gap-2 to gap-1.5

Reduces spacing between icon and McpMux text from 8px to 6px
for a tighter, more cohesive title bar layout.

https://claude.ai/code/session_01J4whZ2FE8DHRZJo7tZeW5m

Author: claude

apps/desktop/src/App.tsx

@@ -198,7 +198,7 @@ function AppContent() {
   );
 
   const titleBar = (
-    <div className="flex items-center gap-2 pl-3">
+    <div className="flex items-center gap-1.5 pl-3">
       <McpMuxGlyph className="h-4 w-4 shrink-0" />
       <span className="text-sm font-bold tracking-tight select-none">
         <span style={{ color: '#E8956A' }}>Mcp</span>