Live close --pr and distill continuation post-merge

[sameera]

As a delivery lead, I want close and distill run post-merge on the scratch repo, so
that the merged-PR gate, the shared distill worktree handoff, and the distillation PR are proven
live rather than assumed.

Acceptance Criteria

• Given a merged PR carrying an analyze review, when close --pr runs, then a
  distill/<date>-<slug> branch exists on the scratch remote carrying the close record and
  the committed queue entry.
• Given close has completed, when distill runs in that same worktree, then a
  distillation PR is open against the scratch trunk containing the concept deltas and the
  deletion of the queue entry it drained.
• Given a PR that is not merged, when close --pr is invoked against it, then
  it exits non-zero with the merge-required diagnostic and creates no branch, worktree, or
  commit.
• Given the chain has completed, when teardown runs, then no worktrees created by
  close or distill remain in the host checkout.
• Given the run is finished, when the acceptance record is read, then it states a
  pass/fail verdict per stage and links every divergence from the injected-runner expectations
  to a filed issue or backlog stub (or records explicitly that there were none).

Notes

This story seals the acceptance record — it depends on STORY-132.02 (the analyze review the close
gate reads) and STORY-132.03 (a merged PR whose range has been independently verified) having
written their slots.

A clean run is a pass: recording explicitly that there were zero divergences satisfies the final
criterion. Fixing anything the dry-run surfaces is out of scope for this epic — each fix is sized
and scheduled separately.

[sameera]

Closed as not-worth-the-cost, 2026-07-25. Same reasoning as #134.

Why. close --pr and distill run for real on the next epic that goes through the flow. The scratch repo would only have let them fail somewhere disposable first. That is worth something, but not worth granting delete_repo to the maintainer's credential — and every failure this story would have caught is a loud one: a missing distill/<date>-<slug> branch, a distillation PR that does not open, a worktree left behind. All are visible at the moment they happen and recoverable by hand.

That is the distinction that drove the re-scope of this epic. A wrong range: is silent and surfaces months later as the wrong concept pages being rewritten; that got kept and measured (#135, 6/6 PASS against this repo's own merge history). A close/distill chain that breaks tells you immediately.

What is not covered as a result. The merge-required gate refusing an unmerged PR, the shared distill worktree handoff, the distillation PR contents, and teardown residue. The first is a pure precondition check already covered by unit tests; the rest are observed directly on the next real run.

Still open and unrepaired: divergence D1 in docs/features/pr-driven-delivery/live-acceptance-record.md — a repo carrying only the vendored .claude/ tree cannot execute the flow, because the commands invoke helpers by repo-relative path and those helpers resolve libraries through workspace links. That was found while building the harness, is unrelated to whether this story runs, and still needs sizing separately.

The nxs-pr-acceptance harness (#133) is retained as the controlled reproduction if the chain ever misbehaves for real.