revert: undo t0ng7u UI design-system refactor

Revert the following commits:
- 308e3e347 feat(web): polish themed data views and add task log details
- b2a890e75 fix: Fontsource asset resolution across workspace layouts
- 9d1ca545e refactor(web): refine data-table cards and pricing page layout
- 0918bdb49 refactor(web): consolidate design-system primitives and responsive data views
- 262ab9312 style(web): unify design system across default frontend

web/default/src/context/theme-provider.tsx

@@ -20,7 +20,7 @@ import {
   createContext,
   useCallback,
   useContext,
-  useLayoutEffect,
+  useEffect,
   useMemo,
   useState,
 } from 'react'
@@ -88,8 +88,7 @@ export function ThemeProvider({
     resolveTheme(getStoredTheme(storageKey, defaultTheme))
   )
 
-  // Apply before paint to avoid a light→dark (or reverse) flash on load.
-  useLayoutEffect(() => {
+  useEffect(() => {
     const root = window.document.documentElement
     const mediaQuery = window.matchMedia('(prefers-color-scheme: dark)')