Add routes to serve each page from the UI build.

Latest Litestar includes `SecretString` type.

Pages are protected by custom auth middleware and endpoints are protected by an auth "guard". At start up, we generate a random authorization token and print it to the console. To log in, users must provide the token to the `login` endpoint. In the UI, this can be accomplished with a post `fetch` request setting `redirect` to "follow" and manually handling the redirect:

```javascript
if (resp.redirected) {
  window.location.href = resp.url;
}
```

We use built-in cookie-based session middleware to keep track of whether users are logged in or not. A user is authenticated if their request contains a session with `token=AUTH_TOKEN`.

In `DEV_MODE`, use secret token "test" to authorize.

This commit relocates `app` from `__init__.py` to `asgi.py`. For a minimal application, `__init__.py` is a reasonable location (and one of the locations where Litestar automatically checks for an `app`), but for a more complex application where we are importing objects from `src/app`, this location becomes problematic.

Closes #54

Fixes volume mount and image path.

Forwards port and uses service `name` instead of `job_id`.

…ackfish into user-interface

Closes #47.