!. install typescript, @types/react and @types/react-dom.
2. in packages.json, replace vite build with tsc && vite build.
3. configure your TS:

tsconfig.json

{
  "compilerOptions": {
    "target": "ESNext",
    "useDefineForClassFields": true,
    "lib": ["DOM", "DOM.Iterable", "ESNext"],
    "allowJs": false,
    "skipLibCheck": true,
    "esModuleInterop": false,
    "allowSyntheticDefaultImports": true,
    "strict": true,
    "forceConsistentCasingInFileNames": true,
    "module": "ESNext",
    "moduleResolution": "Node",
    "resolveJsonModule": true,
    "isolatedModules": true,
    "noEmit": true,
    "jsx": "react-jsx"
  },
  "include": ["src"],
  "references": [{ "path": "./tsconfig.node.json" }]
}

tsconfig.node.json

{
  "compilerOptions": {
    "composite": true,
    "module": "ESNext",
    "moduleResolution": "Node",
    "allowSyntheticDefaultImports": true
  },
  "include": ["vite.config.ts"]
}

pretty easy to do. I wonder why no one made a response like this.
I only know this because I installed a new vite project then copied the config files to the typeless old project. but you don't have to (hopefully not soon)/

HAPPY CODING :)

By default, esbuild is applied to ts, jsx and tsx files, You don't need to specify loaders for esbuild.