Multi-Step Form Wizard

Create a multi-step form wizard with:

## Progress Indicator
- Horizontal step indicator at top: Step 1 → Step 2 → Step 3 → Step 4
- Current step highlighted, completed steps with checkmark
- Step labels: "Account", "Profile", "Preferences", "Review"
- Clickable completed steps to go back

## Step 1 — Account
- Email input with real-time validation
- Password input with strength indicator (weak/fair/strong)
- Confirm password with match validation
- Show/hide password toggle

## Step 2 — Profile
- First name, Last name
- Avatar upload with preview (drag and drop or click)
- Bio textarea with character count (max 200)
- Timezone selector

## Step 3 — Preferences
- Toggle switches: Email notifications, Dark mode, Public profile
- Select dropdown: Language preference
- Radio group: Plan selection (Free, Pro, Enterprise) with feature comparison

## Step 4 — Review
- Summary of all entered information
- Edit buttons to jump back to specific sections
- Terms of service checkbox
- "Create Account" submit button

Use shadcn/ui components. Add smooth slide transitions between steps. Form state persists when navigating between steps. Show validation errors inline.