Build me a simple lead form website that runs on my computer. Use Node.js with no framework, and keep it to a few small files in this folder.

THE FORM (what a buyer lead sees)
One question per screen, big buttons, works on a phone:
1. First name
2. Email
3. Phone
4. When do you want to move? (In the next 30 days / 1 to 3 months / 3 to 6 months / 6 months or more / Just curious)
5. How will you pay? (Pre-approved for a mortgage / Paying cash / Not pre-approved yet / Not sure)
6. Do you need to sell a home first? (Yes / No)
7. Anything else you want me to know? (optional text box)

THE SORTING (Jev from TypeSafe AI, through OpenRouter)
After each answer to questions 4, 5 and 6, ask Jev how hot the lead is and update a live Hot / Warm / Cold meter with the percentages.
- Jev does NOT use the chat completions endpoint. Call POST https://openrouter.ai/api/alpha/decisions with the headers Authorization: Bearer <key> and Content-Type: application/json.
- Request body:
{
  "model": "typesafe/jev-1.13",
  "state": { the answers to questions 4, 5 and 6 so far },
  "questions": {
    "temperature": {
      "type": "choice",
      "instructions": "How ready is this lead to buy a home with an agent soon?",
      "criteria": {
        "hot": "Ready to buy within about 3 months and has financing or cash lined up.",
        "warm": "Serious about buying, but 3 to 6 months out or still getting financing ready.",
        "cold": "Just curious, 6 or more months out, or has no plan yet."
      }
    }
  }
}
- The result is in answers.temperature: "choice", "confidence", and "probabilities" for hot, warm and cold.
- Read the official tutorial first so you get it exactly right: https://openrouter.ai/docs/guides/community/jev-tutorial

SAFETY RULES (don't skip any)
- My OpenRouter key goes in a .env file as OPENROUTER_API_KEY. Only the server reads it. Never put it in the web page. Add .env to .gitignore.
- Only send Jev the answers to questions 4, 5 and 6. Never send the name, email, phone or the "anything else" box. Save those with the lead for me to read myself.
- A lead score must never use race, color, religion, national origin, sex, disability, familial status or age. Those are fair housing protected classes.
- If Jev's confidence is under 0.6, label the lead "Needs a human look" instead of hot, warm or cold.
- Keep the model pinned to typesafe/jev-1.13.

THE ADMIN VIEW
Split the screen: the form on the left (about 60%), and on the right a simple admin panel with the live hot, warm and cold percentages and a list of submitted leads with their final label. Save submitted leads to a leads.json file in this folder.

WHEN YOU'RE DONE
Ask me to paste my OpenRouter key, save it to .env, start the server, and give me the link to open in my browser. Explain anything I need to do in plain English, one step at a time. If I need to install Node.js, tell me exactly how.