docs(pr-preservation): drain-log for #608 (verified equivalent; clean-superseded by #613)

docs/pr-preservation/608-drain-log.md

@@ -0,0 +1,98 @@
+# PR #608 drain log — superseded by #613 (consolidated-backfill); 13:41:52Z row preserved on main
+
+PR: <https://github.com/Lucent-Financial-Group/Zeta/pull/608>
+Branch: `tick-history/2026-04-26T13-42Z` (approximate; refs/pull/608/head canonical)
+Outcome class: **CLOSED-NOT-MERGED** (superseded; 2nd-agent verified equivalent)
+Drain session: 2026-04-26 (Otto, autonomous-loop continuation)
+Total threads drained: 0 (closed during consolidation chain before review activity)
+Rebase context: closed via consolidated-backfill PR #613 absorbing parallel-DIRTY siblings.
+
+Per Otto-250 + task #268 backfill. This drain-log documents the
+clean equivalent-supersession case (no substrate loss; row absorbed
+into #613 then landed on main). Sibling drain-logs (#607-, #612-)
+documented the partial-loss-then-recovery cases for the same
+parallel-tick cohort.
+
+---
+
+## Outcome
+
+- **Opened**: 2026-04-26 ~13:41Z (added single tick-history row at
+  13:41:52Z — task #276 gating discovery + #602 MD032 fix)
+- **Closed**: 2026-04-26 13:55:07Z (superseded by consolidated-backfill
+  PR #613 which absorbed sibling parallel-DIRTY tick-history rows)
+- **Substrate-preservation status**: complete. 13:41:52Z row landed on
+  main via #613 byte-identical to #608's added content.
+- **Branch retention**: retained on origin per Otto-238
+
+## Otto-347 2nd-agent audit verdict (2026-04-26 16:30Z)
+
+VERIFIED EQUIVALENT:
+
+- 13:41:52Z on origin/main — EXACT MATCH to #608's added content
+- No other files modified
+- No substrate lost
+
+## What was on this PR's branch
+
+Single tick-history row added:
+
+**13:41:52Z** — autonomous-loop tick documenting:
+
+1. **Task #276 (direct-to-main tick-history) gating discovery** — confirmed
+   gated on B-0032 heartbeat-file-integrity threat-model review. Filed
+   as understanding, not work; would skip the discipline if implemented
+   today.
+
+2. **PR #602 MD032 lint fail fixed** (push 5cecc81): the absorb doc's
+   verbatim Amara math sections had inline bulleted lists without
+   surrounding blank lines. Auto-fix python script: insert blank line
+   before list-start when prev was non-blank-non-list, blank line after
+   list-end when next was non-blank-non-list. 15 insertions; no content
+   edits, Amara/Gemini verbatim preserved.
+
+3. **Verified the 3 substrate-primitive lints I noted earlier do NOT
+   exist**: `check-jq-add-default.sh`, `check-tick-history-codespan-pipes.sh`,
+   `check-branch-protection-snapshot-stale.sh` — all not in `tools/hygiene/`.
+   Building them is real work; held pending higher-priority items.
+
+The row's content has compound substrate value: it documents Otto-289
+verify-target-exists discipline applied successfully (verified 3 absent
+substrate-primitives), captures task #276 gating context, and tracks
+the #602 MD032 fix that was part of the multi-pass cross-AI math
+review chain landing.
+
+## Pattern observations (Otto-250 training-signal class)
+
+1. **Clean-supersession case**: in contrast to #607 + #612 (where
+   13:38Z + 13:52Z rows got dropped in #618→#620 transition), #608's
+   13:41Z row was successfully absorbed into #613 then to main. Same
+   parallel-tick cohort; different multi-stage path; different outcome.
+   The variable that explains the difference: which consolidated-backfill
+   PR absorbed each row + whether that PR's clean-reapply correctly
+   extracted all the absorbed content. #613 succeeded; #618→#620
+   partially failed; same class of operation, different reliability.
+
+2. **Compound-substrate row but no loss**: even though this row had
+   compound substrate value (Otto-289 verify success + task #276 gating
+   + #602 MD032 fix), the supersession path absorbed it cleanly because
+   #613 was a one-shot consolidated-backfill that didn't undergo the
+   #618→#620 hallucinated-mental-model failure.
+
+3. **The 2nd-agent audit saved time + cost** by confirming this case
+   was clean: the audit ran in ~2 min and verified the byte-identical
+   match against main, freeing the recovery effort to focus on the
+   actual losses (#607's 13:38 + #612's 13:52). Without the audit, I
+   might have done unnecessary recovery work on this PR's content too.
+
+## Composes with
+
+- Otto-238 retractability (closed branch refs preserved indefinitely)
+- Otto-250 PR-reviews-as-training-signals
+- Otto-347 (the 2nd-agent audit that verified this case)
+- 607-drain-log.md + 612-drain-log.md (sibling drain-logs from same
+  parallel-tick cohort; different outcomes documenting why #613
+  succeeded where #618→#620 partially failed)
+- #613 (the consolidated-backfill that absorbed this PR's row)
+- Otto-289 verify-target-exists (the discipline this PR's row documents
+  in action)