Remove unused response bodies from a number of API endpoints.

This removes the response body from the following methods:

* `POST /api/setup`
* `POST /api/auth/login`
* `POST /api/invite/:id`
* `POST /api/password`

The bodies returned from these methods were something of a rough guess as to what might be useful. Actual client development has shown that we don't use _any_ of the data from any of these API responses, so let's not tie ourselves to future compatibility by continuing to send them. We can add a body to a bodyless method a _lot_ more easily than we can change the body of a method that already returns one, after all.

These changes are not backwards compatible for clients which care about the existing bodies. To my knowledge, there are no such clients; the included client definitely doesn't care.

## Internals

Not only does this change stop returning bodies at the API surface, but it also stops retrieving and returning values used internally to construct those responses, simplifying the code a bit in the process.

One side effect of this is that tests that need to log in a user now need to manually verify the returned token secret, to convert it back into a user, whereas the previous versions returned both a token secret and a user during password login. I don't love the increase in the size of the tests, but I think it's the right tradeoff (and this change is code net-negative anyways).

Merges no-content into main.

1 files changed, 3 insertions, 24 deletions

diff --git a/docs/api/initial-setup.md b/docs/api/initial-setup.md
index a3f6506..b52771f 100644
--- a/docs/api/initial-setup.md
+++ b/docs/api/initial-setup.md
@@ -17,8 +17,7 @@ New instances of this service require an initial setup step before they can full
 
 ## Requests before setup completed
 
-Before the service is set up, all API endpoints, other than those specifically documented as exceptions, will return a status of
-`503 Service Unavailable` to all requests.
+Before the service is set up, all API endpoints, other than those specifically documented as exceptions, will return a status of `503 Service Unavailable` to all requests.
 
 Initial setup can be completed only once.
 
@@ -64,29 +63,9 @@ The proposed `name` must be valid. The precise definition of valid is still up i
 
 <!-- This prose is duplicated from authentication.md, with small changes for context. If you edit it here, edit it there, too. -->
 
-This endpoint will respond with a status of
-`200 Okay` when successful. The body of the response will be a JSON object describing the newly-created user:
+This endpoint will respond with a status of `204 No Content` when successful.
 
-```json
-{
-  "id": "Uabcd1234",
-  "name": "Andrea"
-}
-```
-
-The response will include the following fields:
-
-| Field  | Type   | Description                                                                                                                                        |
-| :----- | :----- | :------------------------------------------------------------------------------------------------------------------------------------------------- |
-| `id`   | string | A unique identifier for the newly-created user. This can be used to associate the user with other events, or to make API calls targeting the user. |
-| `name` | string | The user's name.                                                                                                                                   |
-
-The returned name may not be identical to the name requested, as the name will be converted to [normalization form C](http://www.unicode.org/reports/tr15/) automatically. The returned name will include this normalization; the service will use the normalized name elsewhere, and does not store the originally requested name.
-
-The provided password will also be converted to normalization form C. However, the normalized password is not returned to the client.
-
-The response will include a `Set-Cookie` header for the
-`identity` cookie, providing the client with a newly-minted identity token associated with the initial user created for this request. See the [authentication](./authentication) section for details on how this cookie may be used.
+The response will include a `Set-Cookie` header for the `identity` cookie, providing the client with a newly-minted identity token associated with the initial user created for this request. See the [authentication](./authentication) section for details on how this cookie may be used.
 
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