Restyle landing to match aimloperations.com and use piha.lc.

Public short hosts are piha.lc (prod) and beta.piha.li (beta). The root
page is a marketing CTA to contact AI ML Operations for access.
Closes #3.

Implementation.md

@@ -2,7 +2,7 @@
 
 Django 6 service in Docker, packaged with `uv`. First caller is `monica_site` (SMS campaign
 bodies and ad-hoc texts). A short public domain will be pointed at this service later;
-until then a subdomain (for example `go.mkdrealtor.com`) is enough.
+until then a subdomain is enough. Public short hosts: `piha.lc` (prod), `beta.piha.li` (beta).
 
 This document is the build spec. Implement in this repo. Do not fold the shortener into
 `monica_site`.
@@ -69,7 +69,7 @@ cannot mint links without a configured Bearer token. Empty `SHORTENER_API_TOKENS
 ```
 Internet
    │
-   ├─ NPM: SHORT_DOMAIN (mkd.to / go.mkdrealtor.com)
+   ├─ NPM: SHORT_DOMAIN (piha.lc / beta.piha.li)
    │    location ~*^/[a-z0-9]{4,8}$  →  gunicorn   (redirects only)
    │    /api/*                       →  404 / drop
    │    /admin/                      →  404 / drop
@@ -130,7 +130,7 @@ Caller (`monica_site`) is an HTTP client. It does not share this database.
 
 Until the purchased short domain exists:
 
-- Set `SHORT_DOMAIN=go.mkdrealtor.com` (or `localhost:8005` locally).
+- Set `SHORT_DOMAIN=piha.lc` (or `localhost:8005` locally).
 - Codes do not change when DNS is swapped. Only `SHORT_DOMAIN` / `PUBLIC_SHORT_URL` change.
 
 ---
@@ -274,7 +274,7 @@ Response `201`:
 ```json
 {
   "code": "a3k9xm",
-  "short_url": "https://go.mkdrealtor.com/a3k9xm",
+  "short_url": "https://piha.lc/a3k9xm",
   "target_url": "https://mkdrealtor.com/listings/oak-st?utm_source=monica&utm_medium=sms",
   "title": "Oak St listing",
   "is_active": true,
@@ -355,8 +355,8 @@ Reject codes that do not match `^[a-z0-9]{4,8}$` with 404 (no extra work).
 | `DJANGO_DEBUG` | false in prod |
 | `DJANGO_ALLOWED_HOSTS` | public short host **and** API hostname |
 | `DATABASE_URL` | Postgres; empty → SQLite |
-| `SHORT_DOMAIN` | public hostname phones use (`go.mkdrealtor.com` then `mkd.to`) |
-| `PUBLIC_SHORT_URL` | origin for minted URLs, e.g. `https://go.mkdrealtor.com` (no trailing slash) |
+| `SHORT_DOMAIN` | public hostname phones use (`piha.lc` prod, `beta.piha.li` beta) |
+| `PUBLIC_SHORT_URL` | origin for minted URLs, e.g. `https://piha.lc` (no trailing slash) |
 | `SHORT_PUBLIC_HOSTS` | comma list; Host values that only serve redirects |
 | `SHORT_API_HOSTS` | comma list; Host values that serve `/api/` (public API DNS and/or docker name) |
 | `SHORT_ADMIN_HOSTS` | comma list; Host values that serve `/admin/` (default localhost only) |