[bug]: Markdown ignored - rendered as plain-text in work items

Is there an existing issue for this?

• I have searched the existing issues

Current behavior

When issues/PRs sync from GitHub to Plane, markdown formatting in the description is rendered as literal text.
The same underlying issue affects manual paste.

It appears that when both text/html and text/plain are present, it consumes text/html first and the tiptap-markdown extension's transformPastedText path is never reached.

Expected: GitHub issue descriptions render with proper markdown formatting in Plane.
Actual: Raw markdown syntax is displayed as plain text.

The topic of broken markdown formatting has been raised since 2023, but I have not found other issues for the impact it has related to the github integration specifically so maybe this is new -- but it makes the github integration unusable.

Steps to reproduce

For GitHub integration:

1. Connect to github
2. Sync github Issues / PRs as Work Items
3. Create Issue / PR in github with markdown formatting
4. See error

For manual paste:

1. Copy markdown-formatted text from Github issue
2. Create a Work Item in Plane
3. Edit the Work Item description
4. Paste from your clipboard
5. See error

Environment

Production

Browser

Google Chrome

Variant

Cloud

Version

v1.2.3