Add some key-like properties to the voting session

amelie/static/docs/api/v0/openapi-spec.yaml

@@ -61,6 +61,9 @@ components:
                 - uuid
                 - votingUuid
                 - email
+                - secret
+                - createdAt
+                - expiresAt
             type: object
             properties:
                 uuid:
@@ -73,10 +76,27 @@ components:
                 email:
                     type: string
                     format: email
+                secret:
+                    description: A token that can be used as secret to authenticate against the API.
+                    type: string
+                    readOnly: true
+                createdAt:
+                    description: The zoned date and time this session was created at.
+                    type: string
+                    format: date-time
+                    readOnly: true
+                expiresAt:
+                    description: The zoned date and time this session expires at, i.e. after which no ballot can be cast anymore with it.
+                    type: string
+                    format: date-time
+                    readOnly: true
             example:
                 uuid: 1f1a8e45-86eb-4ca0-8e2a-b5cc8c274f06
                 votingUuid: ace5430c-8251-4524-bacb-ae3b2445d70d
                 email: fs-coli@cl.uni-heidelberg.example
+                secret: amelie.ffp3A13knC21zFnb5A-suH_5Q5VwgdjSWz9cZTSI3bs
+                createdAt: "2024-11-04T15:00:02+00:00"
+                expiresAt: "2024-11-05T15:00:02+00:00"
         VotingItem:
             title: VotingItem
             description: “Abstimmungsgegenstand”. One single thing a vote (yes, no, abstention) can be cast on.