Add OpenAPI spec for ticket linked conversations endpoints

[MatthewPelyhes]

Why?

The API supports linking and unlinking conversations to tracker tickets, but the OpenAPI spec has no definitions for these endpoints. Without spec coverage, they won't appear in generated SDK clients (TypeScript, Java, Python, PHP), API explorers, or documentation.

How?

Added two new endpoint definitions to the Preview spec (descriptions/0/api.intercom.io.yaml), following the existing nested ticket sub-resource patterns (tags, change_type):

• POST /tickets/{ticket_id}/linked_conversations — link a conversation to a tracker ticket
• DELETE /tickets/{ticket_id}/linked_conversations/{id} — unlink a conversation from a tracker ticket

Both include full request/response schemas, inline examples, and error response documentation (400, 401, 404).

Implementation Plan

Endpoints Added

POST /tickets/{ticket_id}/linked_conversations

• operationId: linkConversationToTicket
• tags: [Tickets]
• parameters: Intercom-Version header + ticket_id path param
• requestBody: { conversation_id: string } (required)
• 200 response: Conversation object via $ref: "#/components/schemas/conversation"
• 400 response: 5 error examples: parameter_not_found, invalid_ticket_type, already_linked_to_tracker, linked_conversation_limit_exceeded, intercom_version_invalid
• 404 response: 2 error examples: ticket_not_found, conversation_not_found
• 401 response: Standard unauthorized

DELETE /tickets/{ticket_id}/linked_conversations/{id}

• operationId: unlinkConversationFromTicket
• tags: [Tickets]
• parameters: Intercom-Version header + ticket_id + id path params
• No requestBody (all params in path)
• 200 response: Conversation object
• 400 response: 2 error examples: invalid_ticket_type, intercom_version_invalid
• 404 response: 2 error examples: ticket_not_found, conversation_not_found
• 401 response: Standard unauthorized

Design Decisions

1. Tags: [Tickets] only — these are ticket sub-resource operations, matching existing patterns like changeTicketType.
2. Auth: Global bearerAuth — no per-endpoint scope overrides (follows spec convention).
3. DELETE requestBody: Omitted — no body parameters needed.
4. Insertion point: Between /tickets/{ticket_id}/tags/{id} and /tickets — sub-resources are grouped before collection endpoints.

_{Generated with Claude Code}