fix: update getAccount response type from array to single account object

The getAccount endpoint was incorrectly documented as returning an array
of accountMembership objects, but it actually returns a single
accountMembership object. This change updates the OpenAPI specification
to correctly reflect the actual API behavior.

This fix ensures consistency with other similar single-object endpoints
like createAccount, updateAccount, and getCurrentUser.

Fixes #567

Author: CalebBarnes

swagger.yml

@@ -2054,9 +2054,7 @@ paths:
         '200':
           description: OK
           schema:
-            type: array
-            items:
-              $ref: '#/definitions/accountMembership'
+            $ref: '#/definitions/accountMembership'
         default:
           $ref: '#/responses/error'
     put: