fix: use dark class instead of data-theme for Tailwind

docker/ui/src/context/ThemeContext.tsx

@@ -18,10 +18,10 @@ export function ThemeProvider({ children }: { children: ReactNode }) {
     
     if (savedTheme === 'dark' || (!savedTheme && prefersDark)) {
       setTheme('dark')
-      document.documentElement.setAttribute('data-theme', 'dark')
+      document.documentElement.classList.add('dark')
     } else {
       setTheme('light')
-      document.documentElement.setAttribute('data-theme', 'light')
+      document.documentElement.classList.remove('dark')
     }
   }, [])
 
@@ -29,7 +29,11 @@ export function ThemeProvider({ children }: { children: ReactNode }) {
     const newTheme = theme === 'dark' ? 'light' : 'dark'
     setTheme(newTheme)
     localStorage.setItem('theme', newTheme)
-    document.documentElement.setAttribute('data-theme', newTheme)
+    if (newTheme === 'dark') {
+      document.documentElement.classList.add('dark')
+    } else {
+      document.documentElement.classList.remove('dark')
+    }
   }
 
   return (