You are Replit Agent acting as a full‑stack architect and implementer.

## Goal
In this Repl, build the first working version of **Aura**: a domain‑to‑business generator.

Aura should:
- Take a single domain or a CSV list.
- Analyze niches and business models for each domain.
- Generate brand options, site copy, and a “for sale / business‑in‑a‑box” sales letter.
- Serve a simple web UI where I can paste domains, review niches, pick one, and trigger content generation.
- Persist everything to a database.
- Be deployable using Replit’s built‑in Deploy features.

Focus on **end‑to‑end functionality** over polish.

## Replit Environment Requirements

1. Use **Python + FastAPI** for the backend API.
2. Use **Replit DB or a simple SQLite/Prisma/Postgres via Replit DB connector** for persistence (pick the simplest that works well with Replit’s best practices).
3. Provide a minimal **web frontend** using either:
   - FastAPI + Jinja templates, OR
   - A single‑page HTML/JS frontend served from FastAPI.
4. Use **Replit Secrets** for external API keys (DeepSeek/OpenAI/Gemini). Do not hardcode keys.
5. Configure environment using `replit.nix` and `.replit` according to Replit guidelines so the Repl:
   - Starts the FastAPI app on the correct port.
   - Can use the Deploy button without extra manual steps. [web:116][web:120]

## Architecture You Should Implement

### 1) Project Structure

Create this file/folder layout:

- `app/main.py` – FastAPI app with API routes.
- `app/models.py` – DB models / schema definitions.
- `app/services/llm.py` – Wrapper to call an external LLM (DeepSeek/OpenAI/Gemini), reading API keys from environment.
- `app/services/aura.py` – Core Aura logic:
  - `analyze_domain(domain) -> niches JSON`
  - `build_package(domain, chosen_niche) -> package JSON`
- `app/templates/` – Jinja2 templates for the web UI.
- `static/` – CSS/JS for the UI (minimal).
- `scripts/import_csv.py` – CLI script to bulk‑import/analyze domains from a CSV.
- `requirements.txt` – Dependencies.
- `.replit` and `replit.nix` – Properly configured run command and dependencies for Replit. [web:112][web:116]

### 2) Core Features

#### A. Domain & Market Analyzer (Module 1)

Implement `analyze_domain(domain: str)` in `app/services/aura.py`:

- Decompose domain into keywords.
- Call `services/llm.call_llm()` to:
  - Suggest 5–10 niche ideas, including creative angles (acronyms, cross‑language meanings, mashups, cross‑domain tie‑ins).
  - For each niche, return:
    - `name`
    - `description`
    - `monetization_model`
    - `time_to_revenue` (fast/medium/slow)
    - `valuation_band` (e.g., "500‑2000", "5000‑20000")
    - `score` (0–10)
- Store the raw analysis JSON in the DB.
- Expose an API route:
  - `POST /api/analyze-domain` with `{ "domain": "example.com" }` → returns structured JSON.

#### B. Business & Content Generator (Module 2)

Implement `build_package(domain: str, chosen_niche: str)`:

- Pull the niche analysis for that domain from DB.
- Call `call_llm()` to generate:
  - Brand identity:
    - 3 options: `{ name, tagline }`; pick one.
  - Site copy blocks:
    - `headline`, `subheadline`, `hero_body`, `about`, `offer`, `faq_items` (array of Q&A).
  - A **sales letter** for auction/marketplaces (Flippa/Sedo style) that:
    - Explains the niche, why it’s timely, and monetization methods.
- Save this as a “package” record in DB.
- Expose API route:
  - `POST /api/build-package` with `{ "domain": "...", "niche_name": "..." }`.

#### C. Simple Site Renderer (Module 3)

No external hosting yet; just render within Replit:

- Provide a route `GET /site/{domain}` that:
  - Loads the latest package for that domain.
  - Renders `templates/site.html` with the brand and copy injected.
- This is sufficient to screenshot or show to buyers.

#### D. UI Dashboard (Minimal but Functional)

Create a simple dashboard at `/`:

- **Upload or Paste Domain List:**
  - Textarea for single or multi‑line domains.
  - Button “Analyze Domains” → calls `/api/analyze-domain` per domain.
- **Review Step:**
  - Table listing analyzed domains with their top 3 niches and scores.
  - For each domain, dropdown to choose a niche.
  - Button “Generate Package” → calls `/api/build-package`.
- **View Output:**
  - Link “Preview Site” → goes to `/site/{domain}`.
  - Button “View Sales Letter” → modal or separate route (`/sales/{domain}`).

Keep the frontend very simple—HTML + Tailwind CDN or minimal CSS.

### 3) LLM Integration

- In `services/llm.py`, create a `call_llm(prompt: str) -> str` function.
- Read model + key from environment variables:
  - `LLM_PROVIDER` (e.g., "openai", "deepseek", "gemini")
  - `LLM_API_KEY`
- Implement at least one provider (OpenAI or DeepSeek), with clear TODO comments for others.
- Make all prompts deterministic and **include role guidance** (e.g., “You are a domain valuation expert and niche strategist”).

### 4) Replit‑Specific Best Practices

- Set the **run command** in `.replit` to start the FastAPI app with uvicorn, e.g.:
  ```toml
  run = "uvicorn app.main:app --host 0.0.0.0 --port 8000"