Form Handling — React Hook Form + Zod + Server Actions

Forms are where most React applications get messy. A login form starts simple — two inputs and a button. Then you add validation. Then error messages. Then loading states, disabled fields during submission, field-level validation, server errors that map to specific fields... and suddenly you're managing 15 state variables for a four-field form.

The modern stack for forms in React solves this cleanly: React Hook Form manages form state and performance, Zod handles validation with type safety, and server actions handle submission without API route boilerplate.

Why Not Just useState?

Here's the naive approach:

function SignupForm() {
  const [email, setEmail] = useState("");
  const [password, setPassword] = useState("");
  const [confirmPassword, setConfirmPassword