Pin a conversation so it is listed first in the caller's own conversation list.

Access:

Owner only: the caller must be the conversation's initiator. People the conversation is shared with, even with write access, cannot pin it, and their own lists are not affected by the owner's pin.

Behaviour:

Idempotent: pinning an already pinned conversation succeeds and changes nothing. Archived and deleted conversations cannot be pinned. Archiving a pinned conversation removes its pin. Pinning does not change lastActivityAt or updatedAt, so the conversation keeps its place among the other pinned chats.

• Path params: conversationId
• Query params: none
• Body: none