feat(web): scaffold client-side rendered SPA foundation

- feat: initialize Vite project with React 19, React Router 8, TanStack
  Query, Ant Design 6, and Tailwind CSS 4
- feat: add Oxlint with React/TypeScript rules, strict TypeScript
  config, and layered CSS import order
- docs: add decision record for client-rendered Web foundation with
  React, Ant Design, and Tailwind CSS
- docs: create web roadmap defining architecture boundaries and deferred
  dependencies
- build: pin Node.js 24 in mise.toml

web/src/app/providers.tsx

@@ -0,0 +1,15 @@
+import type { PropsWithChildren } from 'react'
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import { App as AntDesignApp, ConfigProvider } from 'antd'
+
+const queryClient = new QueryClient()
+
+export function AppProviders({ children }: PropsWithChildren) {
+  return (
+    <QueryClientProvider client={queryClient}>
+      <ConfigProvider>
+        <AntDesignApp>{children}</AntDesignApp>
+      </ConfigProvider>
+    </QueryClientProvider>
+  )
+}