diff --git a/docs/hygiene-history/ticks/2026/05/15/1003Z.md b/docs/hygiene-history/ticks/2026/05/15/1003Z.md
new file mode 100644
index 0000000000..db85a12796
--- /dev/null
+++ b/docs/hygiene-history/ticks/2026/05/15/1003Z.md
@@ -0,0 +1,66 @@
+| 2026-05-15T10:03:00Z | claude-opus-4-7 | 596e842c | shard: PR #3402 + #3403 merged; 3 post-merge threads on #3403 — substantive correction (my N+1 explanation was reversed-flow) | (PR #3405) | discipline-phrasing correction: at shard write-time PR does NOT yet exist; "N+1 = N open + 1 new this tick will produce" |
+
+# Tick 1003Z — PR #3402 + #3403 merged; substantive correction on N+1 discipline phrasing
+
+## Headline
+
+- **PR [#3402](https://github.com/Lucent-Financial-Group/Zeta/pull/3402)** (0950Z shard) MERGED → `08a326c`.
+- **PR [#3403](https://github.com/Lucent-Financial-Group/Zeta/pull/3403)** (0955Z shard) MERGED → `d89efc1`. 3 post-merge threads on this PR:
+  - **Thread 1 (Codex P2, substantive)**: my 0955Z's N+1 mitigation phrasing was reversed-flow. I said "PR is opened before the shard is committed to its branch" — that's BACKWARDS. Actual flow: write → `git commit` → `git push` → `gh pr create`. PR does NOT exist at shard write-time.
+  - **Thread 2 (Copilot stale)**: `(PR TBD)` claim on col 5; verified `(PR #3403)` on main; templated reply + resolve.
+  - **Thread 3 (Copilot, same as Codex)**: also flagged the reversed-flow phrasing.
+- **Discipline correction**: N+1 still works empirically but for a different reason. Corrected phrasing: "count = N currently open + 1 new PR this tick WILL produce". The shard is on main with the inverted explanation; substrate-honest acknowledgments posted.
+- Cron sentinel `596e842c` armed.
+
+## Δ since 0959Z
+
+| What | At 0959Z | At 1003Z |
+|---|---|---|
+| PR #3402 | OPEN, wait-ci | MERGED (`08a326c`) |
+| PR #3403 | OPEN, wait-ci | MERGED (`d89efc1`); 3 post-merge threads → resolved |
+| In-flight | 2 (#3402, #3403) + this tick = 3 | 1 (#3404) + this tick will produce 1 new = 2 |
+| Cumulative merges | 25 | 27 |
+| N+1 discipline phrasing | reversed-flow explanation | corrected: count = N open + 1 new this tick WILL produce |
+
+## Substrate-honest observations
+
+### Reversed-flow correction on N+1 discipline
+
+The 0955Z shard explained the N+1 count as: "shard's OWN PR is in-flight at write-time (PR is opened before the shard is committed to its branch)". **That sequence is reversed.** The actual flow is:
+
+1. Write shard file (in worktree)
+2. `git add` + `git commit` (commit to branch)
+3. `git push` (push to remote)
+4. `gh pr create` (PR is opened HERE — at the END of the sequence)
+
+So at write-time (step 1), the PR does NOT exist. The PR number isn't known.
+
+The N+1 count still works because we're counting forward: "at write-time, N PRs are currently open + this tick will produce 1 more PR shortly". The empirical correctness is unchanged; the explanation needed correcting.
+
+Codex + Copilot both caught the reversed-flow phrasing. Substrate-honest acknowledgments posted on the merged PR's threads. Future canonicalization should use the corrected sequence.
+
+### Discipline-correction chain
+
+Discipline evolution chain for the count problem:
+
+| Tick | State |
+|---|---|
+| 0940Z | First off-by-one (claimed 6 in-flight, listed 5) |
+| 0947Z | Second off-by-one (said "1 in-flight #3400" but should have been "2") |
+| 0955Z | Lesson recorded: "N enumerated + this tick's PR = N+1" (correct count, wrong explanation) |
+| 0959Z | First application of N+1 |
+| 1003Z (this tick) | Explanation corrected via post-merge thread acknowledgments |
+
+The chain shows iterative substrate refinement under reviewer pressure. Codex/Copilot caught the inverted explanation; the discipline persists; the reasoning is now accurate.
+
+## Cron sentinel
+
+`596e842c` armed.
+
+## Next
+
+Cron-driven. Next tick:
+
+1. Verify PR #3404 + this tick's PR auto-merge fires
+2. Address any new threads
+3. Session steady-state — substrate stable, restraint holds