memory: release PR #42 merged (acb1f78); the tag and the PyPI publication remain Eric's gates

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

Author: acn-ericlaw

memory/open-threads/thread-pack-catch-up-release.md

@@ -3,7 +3,7 @@
   stricter `llm.chat` / `llm.stream` contract (two READ items in the CHANGELOG's Unreleased section). The release is tagged at the
   Java number it catches up to, never an intermediate one; Eric decides when, and tag and publish are his steps. **Prepared
   2026-10-07 (Eric: "the right time for release v4.12.21 for the 4 repos"):** `release/4.12.21` (head `953ba1a`) carries the bump
-  and the CHANGELOG cut `## Version 4.12.21, 10/7/2026`; ruff clean, pytest 187; the PR #42 is OPEN (Eric,
-  2026-10-07) with its description. Next, Eric's gates: merge, tag `v4.12.21`, publish to PyPI.
+  and the CHANGELOG cut `## Version 4.12.21, 10/7/2026`; ruff clean, pytest 187; the PR #42 MERGED 2026-10-07
+  02:16:34Z as merge `acb1f78` (identical to the branch head outside `memory/`, CI green). Next, Eric's gates: tag `v4.12.21`, publish to PyPI.
   → serves: vision-mercury-python
   <!-- id: pack-catch-up-release | created: 2026-10-01 | last_used: 2026-10-01 | uses: 1 | tier: working | origin: 2026-10-02-001146 -->

memory/sessions/2026-10-07-012443.md

@@ -18,6 +18,10 @@ all four repositories from the Java repository's session.
   `release/4.12.21` (head `5ddcc9e`, npm test 182/0).
 - **PR #42 is open (Eric opened the four release PRs himself from the pushed branches)**, its description set from the drafted
   body with the cross-links to mercury-composable #528, mercury #368 and the other pack. Gates remaining: merge, tag, publish to PyPI.
+- **PR #42 MERGED** 2026-10-07 02:16:34Z as merge `acb1f78`; identical to the branch head outside `memory/`, title clean; the local branch
+  deleted (GitHub removed the remote one) and `main` fast-forwarded; one CI read: `ci` and agent-memory passed. The engine twins merged
+  the same minute (mercury-composable #528 squash `b76db298`, mercury #368 merge `28457ccf`). Gates remaining: the tag `v4.12.21` and
+  the PyPI publication.
 
 ## Decisions