Lucent-Financial-Group · AceHack · Apr 29, 2026 · Apr 29, 2026 · Copilot · Apr 29, 2026
diff --git a/docs/AUTONOMOUS-LOOP.md b/docs/AUTONOMOUS-LOOP.md
@@ -252,17 +252,26 @@ exception.
 human maintainer, round 44 — see step 1). Immediately
 before stopping, in this exact order:
 
-1. **Append a row to `docs/hygiene-history/loop-tick-history.md`.**
+1. **Write a per-tick shard file at
+   `docs/hygiene-history/ticks/YYYY/MM/DD/HHMMZ.md`** (per task
-   `docs/hygiene-history/ticks/YYYY/MM/DD/HHMMZ.md`** (per task
+   `docs/hygiene-history/ticks/YYYY/MM/DD/HHMMZ[-NN].md`** (per task
-   `docs/hygiene-history/ticks/YYYY/MM/DD/HHMMZ.md`** (per task
+   `docs/hygiene-history/ticks/YYYY/MM/DD/HHMMZ[-NN].md`** (per task
+   #276 Option B — adopted 2026-04-29 to eliminate the EOF
+   append-hotspot conflict surface that arose with the legacy
+   single-table file). The legacy table at
+   `docs/hygiene-history/loop-tick-history.md` remains the
+   canonical READ surface for pre-shard ticks; the shard
+   directory under `docs/hygiene-history/ticks/` is the
+   canonical WRITE surface for new ticks. Schema (one row per
+   shard, same columns as the legacy table) and rationale are
+   in `docs/hygiene-history/ticks/README.md`. Every tick gets
+   a shard — a no-op speculative-scan tick still gets a
+   shard (minimal-density), because the log is the factory's
+   durable answer to *"is the tick actually running?"* (the
+   commit log undercounts; chat messages evaporate). Write
+   the shard BEFORE the `CronList` call so even an
+   abnormally-stopped tick still leaves evidence it ran.
    Human maintainer, round 44: *"you might as well right a
    history record somewhere on every loop tool right before
-   you check cron"*. The schema and rationale are in the
-   header of that
-   file. Every tick gets a row — a no-op speculative-scan
-   tick still gets a row, because the log is the factory's
-   durable answer to *"is the tick actually running?"* (the
-   commit log undercounts; chat messages evaporate). Append
-   BEFORE the `CronList` call so even an abnormally-stopped
-   tick still leaves evidence it ran.
+   you check cron"*.
 2. **Call `CronList`.**
 3. **If `<<autonomous-loop>>` is present at cadence
    `* * * * *`:** do nothing to the scheduler — the cron

diff --git a/docs/hygiene-history/ticks/README.md b/docs/hygiene-history/ticks/README.md
@@ -0,0 +1,119 @@
+# Tick-history shard files
+
+This directory holds **per-tick shard files** for autonomous-loop
+liveness evidence. One shard per autonomous-loop tick.
+
+## Why shards exist
+
+The single end-of-file table at
+`docs/hygiene-history/loop-tick-history.md` produced an "Append-
+Hotspot Merge Friction" failure mode (named by the deep-research
+external-AI reviewer 2026-04-29): every tick-history PR added a
+row to the same EOF surface, and parallel in-flight PRs
+conflicted with each other, generating recursive maintenance work.
+
+Per task #276 architectural choice (per-tick shard files —
+"Option B"), each tick now writes a unique shard file at:
+
+```
+docs/hygiene-history/ticks/YYYY/MM/DD/HHMMZ.md
+```
+
+Per-tick uniqueness eliminates the conflict surface entirely.
+
+## Shard file schema
+
+Each shard is a single-row Markdown file. Required first line:
+
+```
+| <ISO 8601 UTC timestamp> | <model id> | <cron sentinel> | <body> | <PR ref> | <observation> |
+```
+
+Same column structure as the legacy single-table format. A
+generator script (follow-up work) collates shards into the
+legacy table on cadence; until that lands, the legacy table is
+the authoritative read surface and shards are the authoritative
+write surface — both are canonical.
+
+## Naming
+
+```
+docs/hygiene-history/ticks/2026/04/29/0210Z.md
+docs/hygiene-history/ticks/2026/04/29/0215Z.md
+docs/hygiene-history/ticks/2026/04/30/0900Z.md
+```
+
+- Year / month / day are zero-padded numeric folders.
+- Filename is HHMMZ (zero-padded hour + minute, UTC, with `Z`
+  suffix).
+- Extension `.md` so each shard is independently grep-able and
+  rendered by the docs viewer.
+
+If a tick lands within the same minute as a prior tick (rare —
+the autonomous-loop cron is `* * * * *`), append `-01`, `-02`,
+... to disambiguate: `0215Z-01.md`, `0215Z-02.md`.
+
+## What goes in a shard
+
+The same content that previously appended as a row to the legacy
+table:
+
+- Material state-transition ticks → rich shard (multiple
+  paragraphs covering the transitions + observations)
+- Pure-maintenance / no-op ticks → minimal shard (one or two
+  sentences)
+
+Per the corrected liveness doctrine (see
+`docs/AGENT-BEST-PRACTICES.md` operational standing rules
+section "Session-closure rule"): every tick gets a shard.
+Density depends on whether material state changes happened.
+
+## Composition with the legacy table
+
+For the gap before the generator script lands, the legacy table
+at `docs/hygiene-history/loop-tick-history.md` remains the
+canonical READ surface for past history, and new shards in this
+directory become the canonical WRITE surface for new ticks.
+
+Future generator behavior:
+
+```text
+Generator (cadence: post-merge or daily):
+  1. Read all shards under docs/hygiene-history/ticks/**/*.md
+  2. Sort by filename (chronological by file naming)
+  3. Format as legacy-table rows
+  4. Append to docs/hygiene-history/loop-tick-history.md
+  5. Optionally retire shards older than N days to a compressed archive
+```
+
+The generator is follow-up work tracked under task #276.
+
+## Why per-tick rather than per-day or per-PR
+
+- **Per-tick**: each tick writes one file; no collision; no
+  generator pressure beyond mere collation; smallest write unit.
+- Per-day or per-PR would re-introduce append-hotspot inside the
+  bucket. Per-tick removes the hotspot at the file granularity.
+
+The choice was made 2026-04-29 per the converged stance from
+the multi-AI synthesis arc + Aaron's explicit delegation
+(*"this falls under your call"*).
+
+## What this directory does NOT do
+
+- Does NOT replace the legacy table for past history (that
+  remains the canonical READ surface for pre-shard ticks).
+- Does NOT change the AUTONOMOUS-LOOP.md liveness invariant —
+  every tick still gets canonical evidence.
+- Does NOT remove the markdownlint / chronological-order checks
+  — those still apply at the shard-file level.
- Does NOT remove the markdownlint / chronological-order checks
-  — those still apply at the shard-file level.
+- Does NOT remove validation: markdownlint still applies to
+  shard files, and chronological-order checking still applies
+  to `docs/hygiene-history/loop-tick-history.md`.
- Does NOT remove the markdownlint / chronological-order checks
-  — those still apply at the shard-file level.
+- Does NOT remove validation: markdownlint still applies to
+  shard files, and chronological-order checking still applies
+  to `docs/hygiene-history/loop-tick-history.md`.
+- Does NOT introduce a new tick-history schema — same column
+  structure as the legacy table, one row per shard.
+
+## Migration of historical content
+
+The legacy table at `docs/hygiene-history/loop-tick-history.md`
+is NOT migrated to shard files. Pre-2026-04-29-shard ticks stay
+in the legacy table. Post-shard ticks go in shards. The
+generator (follow-up) collates shards into the legacy table to
+preserve the single-table read experience.