hygiene(#268+): pr-preservation drain-log for #422 (correction-row pattern)

docs/pr-preservation/422-drain-log.md

@@ -0,0 +1,122 @@
+# PR #422 drain log — drain follow-up to #403: tick-history correction-row pattern
+
+PR: <https://github.com/Lucent-Financial-Group/Zeta/pull/422>
+Branch: `drain/403-tick-history-correction-row`
+Drain session: 2026-04-25 (Otto, sustained-drain-wave during maintainer-
+asleep window; pre-summary-checkpoint earlier in this session)
+Thread count at drain: 4 Copilot post-merge threads on the parent #403
+tick-history append.
+Rebase context: clean rebase onto `origin/main`; no conflicts.
+
+Per Otto-250 (PR review comments + responses + resolutions are
+high-quality training signals): full record of the four post-merge
+clarifications captured via the **append-only correction-row**
+pattern (Otto-229 discipline).
+
+This PR is the canonical example of the Otto-229 append-only
+discipline applied to tick-history rows: when post-merge review
+surfaces clarifications about an already-merged tick row, the
+correction goes in a NEW row pointing back at the original
+timestamp — never an in-place edit of the merged row.
+
+---
+
+## Threads — four clarifications captured in one correction row
+
+### Thread 1 — Otto-NNN cluster placeholder should have been Otto-279
+
+- Reviewer: copilot-pull-request-reviewer
+- Severity: P2
+- Finding: parent #403 tick-history row had "Otto-NNN cluster" as a
+  placeholder in the session-cluster column; should have been
+  "Otto-279 cluster" specifically (the load-bearing Otto on that
+  tick — research-as-history surface-class refinement).
+- Outcome: **APPEND-ONLY CORRECTION-ROW (Otto-229)** — original row
+  stays untouched; correction row points back at the original
+  timestamp + records "should have been Otto-279 cluster" with
+  context.
+
+### Thread 2 — "Three-thread day" vs (a)-(f) enumeration inconsistency
+
+- Reviewer: copilot-pull-request-reviewer
+- Severity: P2
+- Finding: parent row narrated SIX sub-actions but said "three-thread
+  day" in summary text. "Three-thread day" referred informally to
+  three drain *PRs* in flight (#282, #398, #401) plus three new
+  BACKLOG / refinement landings — NOT three discrete tick threads.
+  Read the (a)-(f) enumeration as the canonical per-action list.
+- Outcome: **APPEND-ONLY CORRECTION-ROW** — disambiguation captured
+  in the new row.
+
+### Thread 3 — Memory file path: forward-mirror landed in #405
+
+- Reviewer: copilot-pull-request-reviewer
+- Severity: P2
+- Finding: parent row cited Otto-279 memory file via global Anthropic
+  AutoMemory path; file has since been forward-mirrored into in-repo
+  `memory/feedback_research_counts_as_history_first_name_attribution_for_humans_and_agents_otto_279_2026_04_24.md`
+  (landed in PR #405).
+- Outcome: **APPEND-ONLY CORRECTION-ROW** — the path resolves
+  correctly now via the in-repo location; correction row notes
+  the post-tick forward-mirror landing.
+
+### Thread 4 — MAME / FBN naming canonical = FBNeo
+
+- Reviewer: copilot-pull-request-reviewer
+- Severity: P2
+- Finding: parent row used "FBN" inconsistently for brevity; the
+  canonical project name is **FBNeo** (not "FBN"). Lowercased
+  `fbneo` may still appear as an EmulationStation/libretro-style
+  slug, distinct from the project's display name. (No folder claim:
+  per-board BIOS requirement kept MAME/FBNeo out of the
+  BIOS-availability-filtered tree.)
+- Outcome: **APPEND-ONLY CORRECTION-ROW** — naming clarification
+  captured.
+
+---
+
+## Pattern observations (Otto-250 training-signal class)
+
+1. **Otto-229 append-only correction-row is the canonical pattern
+   for tick-history clarifications.** When post-merge review
+   surfaces clarifications on an already-merged tick row, the
+   correction row points back at the original timestamp rather
+   than editing the original row in-place. Original row stays
+   intact as historical record of what was believed at that
+   timestamp; correction row records what we now know. Same
+   discipline as ADR-supersedes-ADR pattern; preserves audit
+   trail.
+
+2. **Drain-subagent dispatch prompts must include the Otto-229
+   constraint.** This was the originating finding behind Otto-229:
+   a subagent was caught on PR #364 normalising
+   `May-01` → `2026-05-01` in a prior tick-history row "for
+   consistency." Absence of an explicit constraint in the dispatch
+   prompt looked like permission. Fix: every drain-subagent
+   dispatch targeting tick-history or hygiene-history files must
+   carry "Constraint: do NOT edit existing rows — only APPEND new
+   rows or correction rows."
+
+3. **Single correction row can capture multiple clarifications.**
+   #422 captured four distinct clarifications in one correction
+   row pointing back at the parent's timestamp. The pattern
+   composes: one tick → one parent row + zero-or-more correction
+   rows pointing back at the parent's timestamp + one-or-more
+   clarifications per correction row.
+
+4. **Forward-mirror-landed-after-tick is its own correction
+   sub-class.** Thread 3 captures a particularly clean example:
+   the parent row was correct at authoring time (memory file was
+   in AutoMemory, not in-repo); a subsequent PR #405 landed the
+   forward-mirror; the path is now resolvable in-repo. The
+   correction-row notes the post-tick state-shift without
+   asserting the original was wrong.
+
+## Final resolution
+
+All 4 threads resolved via single append-only correction row.
+PR auto-merge SQUASH armed; CI cleared; PR merged to main as
+`043189e`.
+
+Drained by: Otto, sustained-drain-wave during maintainer-asleep
+window 2026-04-25, cron heartbeat `f38fa487` (`* * * * *`).