docs: note PR author and signed commits for AI writeback

Author: mintlify[bot]

guides/ai-agents/ai-writeback.mdx

@@ -49,6 +49,16 @@ When you ask the agent for a change that belongs in the repo, it calls a tool ca
 
 The tool call is synchronous and can take a few minutes. The agent will tell you a pull request is being prepared while it waits.
 
+## Pull request attribution
+
+Writeback pull requests are opened **as the GitHub user who connected the Lightdash GitHub App to your organization**, not as the Lightdash bot. Commits are authored by that same user and **signed by GitHub** (created through the GitHub API on behalf of the user), so they appear as **Verified** in the GitHub UI and count toward branch protection rules that require signed or verified commits.
+
+A few things to know:
+
+- The connecting user must keep their GitHub authorization for the Lightdash App active. If their token can't be refreshed, writeback falls back to opening the pull request as the `lightdash-app[bot]` with unsigned commits authored by `Lightdash <developers@lightdash.com>`.
+- Attribution is currently **per organization**, not per chat requester. Every writeback PR from your org is attributed to the same connecting GitHub user, regardless of who asked the agent for the change. The original requester is recorded in the chat thread and in the PR description, not on the commit.
+- Because the PR author is a real GitHub user, that user receives the usual GitHub notifications (review requests, CI failures, etc.) for writeback PRs.
+
 ## Using it in chat
 
 Phrase your request as a direct change to the repo and, where possible, name the file, model, or field you want touched. The more specific you are, the more reliably the writeback agent finds the right place to edit.