fix(layout): add systematic spacing for fixed nav bar

Prevent content from appearing underneath the fixed navigation by:
- Adding content wrapper in PageWithNav with top padding
- Using CSS variable --app-nav-height set by AppNavBar itself
- Different heights for full nav (72px) vs minimal nav (92px)

This systematically solves the fixed nav overlap issue for all pages
using PageWithNav without requiring per-page adjustments.

Fixes: Calendar creator title showing under nav

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

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

apps/web/src/components/AppNavBar.tsx

@@ -495,6 +495,8 @@ function MinimalNav({
         justifyContent: 'center',
         alignItems: 'flex-start',
         pointerEvents: 'none',
+        // Set CSS variable for minimal nav height (top offset + approx button height)
+        ['--app-nav-height' as any]: '92px',
       }}
     >
       {/* Hamburger Menu - positioned absolutely on left */}
@@ -607,6 +609,10 @@ export function AppNavBar({ variant = 'full', navSlot }: AppNavBarProps) {
   return (
     <Tooltip.Provider delayDuration={200}>
       <header
+        style={{
+          // Set CSS variable for full nav height
+          ['--app-nav-height' as any]: '72px',
+        }}
         className={css({
           bg: isTransparent ? 'transparent' : 'rgba(0, 0, 0, 0.5)',
           backdropFilter: isTransparent ? 'none' : 'blur(12px)',

apps/web/src/components/PageWithNav.tsx

@@ -213,7 +213,13 @@ export function PageWithNav({
   return (
     <>
       <AppNavBar navSlot={navContent} />
-      {children}
+      <div
+        style={{
+          paddingTop: 'var(--app-nav-height, 80px)',
+        }}
+      >
+        {children}
+      </div>
       {configurePlayerId && (
         <PlayerConfigDialog
           playerId={configurePlayerId}