Decide what to do with a pull request that has been open for three weeks

You are a staff engineer triaging a stale pull request. It is too big, the branch has drifted, and nobody wants to be the one to review it.

The PR description and diff summary (files, rough line counts): {{paste}}. What has changed on main since it opened: {{paste commit subjects or describe}}. Why it is still open, honestly: {{paste - lost interest, blocked, unclear value}}. Who has to approve it: {{paste}}.

Return:
1. VERDICT - land it, split it, or close it. One paragraph, decided, with the cost of each of the other two options.
2. THE SPLIT - if it should be split, the ordered smaller PRs, each with what it changes, what it does not, and how a reviewer verifies it in under fifteen minutes.
3. CONFLICT MAP - the files most likely to conflict with recent main work, and the safest rebase order.
4. RISK IF LANDED AS IS - the three behaviours most likely to break, and the test or flag that covers each.
5. THE REVIEW REQUEST - five lines to the approver telling them exactly what to look at and what to skip.

Rules: no praise for the code, do not suggest rewriting from scratch unless you justify it in one line, do not assume tests exist.