Rebuild all menus from scratch for pixel-perfect rendering on every device

- mobile-nav: pure block/hidden toggle, no transforms, no transition-all
- nav-dropdown: clean block/hidden toggle, no CSS animation hacks
- navigation: removed shadow-sm, no will-change, no GPU compositing
- top-header: consistent mobile layout, clean details/summary dropdowns
- admin-mobile-wrapper: inline transition instead of CSS class for sidebar
- globals.css: removed transition-all from nav-item/dropdown-item, replaced
  with specific color/background-color transitions only, added hover bg

src/app/globals.css

@@ -205,7 +205,8 @@ summary,
 		letter-spacing: 0.03em;
 		text-transform: uppercase;
 		white-space: nowrap;
-		transition: color 0.15s ease-in-out;
+		transition: color 0.15s ease-in-out, background-color 0.15s ease-in-out;
+		border-radius: 0.5rem;
 	}
 	.nav-item::after {
 		content: "";
@@ -224,10 +225,12 @@ summary,
 	}
 	.nav-item:hover {
 		color: var(--color-primary-readable, var(--color-primary));
+		background-color: color-mix(in srgb, var(--color-primary) 8%, transparent);
 	}
 	.dropdown-item {
-		@apply block py-2.5 px-4 text-sm font-semibold transition-all duration-100 rounded-lg mx-1;
+		@apply block py-2.5 px-4 text-sm font-semibold rounded-lg mx-1;
 		color: var(--color-dropdown-text-readable, var(--color-text-readable));
+		transition: background-color 0.1s ease-in-out, color 0.1s ease-in-out;
 	}
 	.dropdown-item:hover {
 		background-color: color-mix(in srgb, var(--color-primary) 12%, transparent);