Add half-body portrait support: update API, UI, and localization for new portrait type

docs/protocol.md

@@ -264,7 +264,7 @@ overload does not slow walking. `hasLocker` is true when the pupil has an assign
 is how many items remain at home, not the list. The people list does not include any of these
 fields. Today's history is a separate GET.
 
-`hasAvatar` and `hasFullBody` tell the client whether PNG files already exist on disk for this
+`hasAvatar`, `hasHalfBody` and `hasFullBody` tell the client whether PNG files already exist on disk for this
 person. They are filled on the HTTP thread after the worker returns the card; generation does
 not happen on this request.
 
@@ -318,6 +318,7 @@ not happen on this request.
   "hasLocker": false,
   "homeCount": 3,
   "hasAvatar": false,
+  "hasHalfBody": false,
   "hasFullBody": false
 }
 ```
@@ -357,15 +358,15 @@ the action or apparel def the caption was built from.
 
 ### `GET /api/schools/{id}/people/{personId}/portrait`
 
-Returns a generated PNG when one exists. Query `kind=avatar|full` selects head-and-shoulders or
-full-body. Unknown school is `404` `unknown-school`; unknown person is `404` `unknown-person`;
+Returns a generated PNG when one exists. Query `kind=avatar|half|full` selects head-and-shoulders,
+waist-up or full-body. Unknown school is `404` `unknown-school`; unknown person is `404` `unknown-person`;
 missing file is `404` `portrait-missing`. Invalid `kind` is `400` `invalid-query`. Content-Type
 is `image/png`. Opening the card does not generate; use POST when the player asks.
 
 ### `POST /api/schools/{id}/people/{personId}/portrait`
 
 Generates (or regenerates) a portrait through SwarmUI on the server. Same `kind` query as GET.
-Success is `201` with `{ "kind", "hasAvatar", "hasFullBody" }` and a `Location` header pointing
+Success is `201` with `{ "kind", "hasAvatar", "hasHalfBody", "hasFullBody" }` and a `Location` header pointing
 at GET. SwarmUI is not configured when `SwarmUi:BaseUrl` is empty — `503` `swarmui-not-configured`.
 Swarm errors are `502` `swarmui-unavailable`; a slow backend is `504` `swarmui-timeout`. Files
 land under `saves/{id}.portraits/` and survive until the school is deleted.