# Hosting Site Creation — Require Merchant or Prospect

## Problem

`hosted_site_service.create()` (lines 118-131) auto-creates a fake "HostWizard System" `Merchant` with no `owner_user_id` as a placeholder to satisfy the Store's `merchant_id` FK. This is wrong on two levels:

- Crashes because `Merchant.owner_user_id` is `nullable=False`
- Conceptually wrong — POC sites should belong to a real entity

## Current Flow

```
create()  → invents a system merchant (broken)
             → creates Store under it
             → creates HostedSite

create_from_prospect()  → reads prospect data
                         → calls create() (same broken path)

accept_proposal()  → creates real merchant
                    → reassigns store to it
```

## Proposed Design: Require merchant_id OR prospect_id

### Schema (`HostedSiteCreate`)

- Add `merchant_id: int | None` and `prospect_id: int | None`
- Add `model_validator`: at least one must be provided
- Remove `prospect_id` from the separate URL path endpoint — unify into one create endpoint

### Service (`create`)

- **If `merchant_id` provided**: validate merchant exists, create Store under it directly
- **If `prospect_id` provided** (no merchant): auto-create a merchant from prospect data using `merchant_service.create_merchant_with_owner()` (same as `accept_proposal` does today), then create Store under it
- **If both provided**: use the existing merchant, link the prospect
- Remove the system merchant creation entirely (lines 118-131)

### `create_from_prospect` method

Can be removed — its logic merges into `create` via the `prospect_id` field.

### `accept_proposal`

Simplify — merchant already exists at this point, so it only needs to handle subscription creation and prospect status update. The store reassignment is no longer needed.

## Files to Change

| File | Change |
|---|---|
| `hosting/schemas/hosted_site.py` | Add `merchant_id`, `prospect_id` fields + validator |
| `hosting/services/hosted_site_service.py` | Rewrite `create()` to use provided merchant or create from prospect. Remove `create_from_prospect()`. Simplify `accept_proposal()`. |
| `hosting/routes/api/admin_sites.py` | Remove `/from-prospect/{prospect_id}` endpoint. The main `POST /sites` handles both paths now. |
| `hosting/templates/hosting/admin/site-new.html` | Add merchant selector (dropdown/autocomplete) and prospect selector. Validate one is chosen. |
| `hosting/tests/conftest.py` | Update `hosted_site` fixture to pass `merchant_id` |
| `hosting/tests/unit/test_hosted_site_service.py` | Update all `create` calls, remove `TestHostedSiteFromProspect` class (merge into main tests), add validation tests for the "at least one required" rule |

## Template Changes Needed

The form currently has a business name + contact fields + a prospect ID input at the bottom. It needs:

1. A **merchant selector** (autocomplete dropdown searching existing merchants)
2. A **prospect selector** (autocomplete dropdown searching existing prospects)
3. Validation: at least one must be selected
4. When prospect is selected: auto-fill business_name, contact fields from prospect data
5. When merchant is selected: auto-fill business_name from merchant name

## What Gets Deleted

- The entire "HostWizard System" merchant pattern (lines 118-131 in service)
- The `POST /sites/from-prospect/{prospect_id}` endpoint
- The `create_from_prospect()` service method
- The prospect ID number input in the template (replaced by proper selector)