A thread has a publication time and an activity time. PalmX stores activity separately so a new reply can bring a conversation back to the top without rewriting when the original post was published.
This keeps archive history honest while making live conversation discoverable.
PalmX treats P2 as a publishing pattern, not a separate database model. Posts stay in wp_posts, comments stay in wp_comments, and users remain WordPress users.
The companion plugin adds the small amount of workflow state needed for front-end posting, inline editing, reply actions, and activity ordering.
The notification path is also native: @horsepress is referenced from this reply, while the thread and activity timestamp remain WordPress data.
A native WordPress comment can bring this thread back to the top without changing the original post date. @horse this is the activity-time example.
The nested reply stays in WordPress comment_parent, so the thread remains native while the activity time updates.