MPT-19028 Add helpdesk chat messages service

[jentyk]

Summary

• introduce ChatMessagesService/AsyncChatMessagesService with full CRUD/list mixins and shared config under /public/v1/helpdesk/chats/{chat_id}/messages
• expose chats().messages(chat_id) on both sync and async chat services and wire new resource into tests
• add unit coverage for endpoint wiring/method presence plus dedicated helpdesk chat messages e2e suites covering list/create/update/delete and error paths

Testing

• Not run (not requested)

Closes MPT-19028

• Add ChatMessagesService and AsyncChatMessagesService with full CRUD and collection capabilities
• Mount chat messages service at /public/v1/helpdesk/chats/{chat_id}/messages
• Expose chats().messages(chat_id) factory method on both synchronous and asynchronous chat services
• Add unit test coverage for endpoint wiring and method presence verification
• Add comprehensive end-to-end test suites for list, create, update, delete, and error handling operations

[coderabbitai]

📝 Walkthrough

Walkthrough

This PR introduces Helpdesk Chat Messages support by adding a new service module with synchronous and asynchronous clients providing CRUD operations. It integrates chat messages into existing chat services via accessor methods and includes comprehensive unit and end-to-end test coverage.

Changes

Cohort / File(s)	Summary
Service Implementation mpt_api_client/resources/helpdesk/chat_messages.py, mpt_api_client/resources/helpdesk/chats.py	New ChatMessage model and ChatMessagesService/AsyncChatMessagesService classes with Create, Update, Delete, and Collection mixins. Integration of messages() accessor methods in ChatsService and AsyncChatsService to route to chat message services with proper endpoint parameters.
Unit Tests tests/unit/resources/helpdesk/test_chat_messages.py, tests/unit/resources/helpdesk/test_chats.py	Test fixtures and parameterized tests verifying CRUD method presence on both sync and async chat message services. Validation of messages() accessor factory behavior and endpoint parameter configuration.
E2E Tests tests/e2e/helpdesk/chats/messages/conftest.py, tests/e2e/helpdesk/chats/messages/test_sync_messages.py, tests/e2e/helpdesk/chats/messages/test_async_messages.py	Test fixtures for chat message service instantiation, message creation/deletion context managers, and payload templates. End-to-end tests for list, create, update, delete operations and 404 error handling on both synchronous and asynchronous endpoints.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~12 minutes

Possibly related PRs

• PR #227: Introduces ChatsService for Helpdesk chats resource, providing the foundation that this PR extends with ChatMessages support and accessor methods.

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The pre-merge checks have been overridden successfully. You can now proceed with the merge.

Overridden by @jentyk via checkbox on 2026-03-16T17:19:14.639Z.

❌ Failed checks (1 error)

Check name	Status	Explanation	Resolution
Jira Issue Key In Title	❌ Error [IGNORED]	The PR title 'Add helpdesk chat messages service' does not contain a Jira issue key in the format MPT-XXXX.	Update the PR title to include the Jira issue key, e.g., 'MPT-19028: Add helpdesk chat messages service'.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Test Coverage Required	✅ Passed	The PR modifies 2 code files in the main codebase and includes 5 test files across both unit and end-to-end test suites.
Single Commit Required	✅ Passed	The PR contains exactly one commit (be51463: Implement Helpdesk chat messages) as verified by git history, meeting the requirement for clean git history.

📝 Coding Plan

• Generate coding plan for human review comments

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[jentyk]

@coderabbitai review

[coderabbitai]

✅ Actions performed

Review triggered.

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