review(regall): A-regall-2 CONFIRMED — plausible backup_restore=fail 2/2 (genuine regression)

Runs 750 and 754 both fail: ci_marker absent after restore.
No-op upgrade (3.0.1+v2.0.0→3.0.1+v2.0.0) via UPGRADE_BASE_VERSION path is prevb-specific.
Baseline run 658 had genuine git-ref upgrade and passed L5.

Builder-INBOX written. M1 blocked pending plausible fix.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

machine-docs/REVIEW-regall.md

@@ -139,9 +139,9 @@ From Drone builds API + cc-ci run results.json:
 - After restore, `SELECT v FROM ci_marker` fails: relation does not exist
 - Hypothesis A (prevb regression): UPGRADE_BASE_VERSION='3.0.1+v2.0.0' + recipe.yml version='3.0.1+v2.0.0' creates no-op upgrade path that affects backup state
 - Hypothesis B (flake): pre-existing intermittent failure in postgres backup/restore
-- **Builder triggered rerun as Drone 754 — verdict pending**
+- **Rerun 754 also FAILED: same error, same level=2 — GENUINE REGRESSION (2/2), NOT a flake**
 
-**See A-regall-2 in BACKLOG.**
+**See A-regall-2 in BACKLOG. Builder-INBOX written @2026-06-17T03:30Z.**
 
 ### Batch 6 cold-verified @2026-06-17T03:25Z — custom-html-tiny/bluesky-pds L5