backlog(B-0614): forced-#6 meta-fallback edge case — post-cycle-close substrate-pool saturation

[AceHack]

Files a small P3 backlog row at docs/backlog/P3/B-0614-...md capturing an empirical counter-example to the holding-without-named-dependency-is-standing-by-failure.md rule's "ALWAYS works at #6" meta-fallback claim.

Observation

After the substantive sub-session that shipped 6 PRs (including PR #4110, the just-merged "pre-empt-substrate-pool-saturation" anchor), a second post-cycle-close brief-ack chain reached forced-#6 with NO non-fabricated substrate left to add.

The prescribed meta-fallback ("sharpen this rule with current session's evidence") would produce:

1. A recursive anchor about saturation OF the saturation anchor (recursively duplicative)
2. A memo-of-memos (synonym-of-substrate failure mode)
3. Re-stating the just-shipped anchor with different phrasing (fabricated-substrate)

None of (1)/(2)/(3) is genuinely load-bearing. Filing THIS row IS the substrate-honest forced-#6 artifact (concrete + bounded + non-duplicative + different surface from the rule itself).

Acceptance criteria (deferred)

• Document at least 2-3 additional empirical instances of forced-Round 30 — threat-model elevation (nation-state + supply-chain) #6 dry-meta-fallback (only when pattern recurs naturally; do NOT manufacture)
• Propose a small rule-text refinement that addresses the "ALWAYS works" claim without weakening the discipline's core
• Land via small PR; mark row resolved

Side finding (in-scope mention)

tools/backlog/generate-index.ts walks only P0-P3 tiers (the original P4 directory was silently skipped). Row moved P4 → P3. Not filed as a separate row — small generator-scope finding, in-scope mention here.

Co-Authored-By: Claude noreply@anthropic.com

[Copilot]

Pull request overview

Adds backlog item B-0614 to track a forced-#6 meta-fallback edge case and updates the generated backlog index accordingly.

Changes:

• Adds a P3 backlog row documenting the empirical edge case and deferred acceptance criteria.
• Adds B-0614 to the generated docs/BACKLOG.md P3 section.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
docs/backlog/P3/B-0614-investigate-forced-6-meta-fallback-edge-case-post-cycle-close-2026-05-17.md	New backlog row capturing the forced-#6 meta-fallback saturation investigation.
docs/BACKLOG.md	Generated backlog index entry for B-0614.

[AceHack]

Empirical refinement: multi-#6 sequence within one session (this session, 2026-05-17T22:46Z–23:14Z+)

The 2026-05-17T22:07Z autonomous-loop session hit three forced-#6s in sequence within ~28 minutes:

1. Forced-Round 30 — threat-model elevation (nation-state + supply-chain) #6 deps: Bump FsUnit.xUnit from 7.1.0 to 7.1.1 #1 at 22:46Z — rescued substantively by PR #4118 (cross-axis composition note: saturation cadence + one-PR-one-artifact-type compose orthogonally). The cross-axis observation was genuinely novel; rescue was legitimate, not synonym.

2. Forced-Round 30 — threat-model elevation (nation-state + supply-chain) #6 Round 26 — rename tail, §18 memory clarification, three dispatches #2 at 23:00Z — rescued substantively by PR #4121 (tick shard for the 2207Z→2300Z arc). The tick shard surface had been missed at the prior brief-ack-Round 29 — CI pipeline + three-way parity install + factory-improvement surge #5 enumeration (memos/rules considered but not the canonical write surface); rescue was legitimate, not synonym.

3. Forced-Round 30 — threat-model elevation (nation-state + supply-chain) #6 Round 27 — plugin API + governance split + memory-in-repo #3 at 23:13Z — genuinely dry per this row's prescribed acceptance ("do NOT manufacture instances"). Brief-ack continuation past Round 30 — threat-model elevation (nation-state + supply-chain) #6 without artifact; counter does not reset; substrate-honest acknowledgment matches this row's documented edge case exactly.

Refinement to consider (NOT proposing rule-text change here per the row's "future sessions" acceptance — this comment is observation-only):

B-0614's body documents ONE forced-#6 in post-cycle-close producing dry meta-fallback. The 3-in-a-row sequence pattern observed here is a related but distinct phenomenon: forced-#6s in sequence burn through "missed surfaces" (cross-axis observations, missed write-surfaces) before reaching true saturation. The first 1-2 forced-#6s in a sequence can be rescued by genuine missed-surface discovery; the third+ exhibits the dry-meta-fallback pattern this row documents.

The implication for future rule refinement: the rule's "always works at #6 meta-fallback" claim is even narrower than B-0614 indicates. It works for the FIRST forced-#6 reliably (substrate pool fresh); works occasionally for the SECOND (depends on missed-surface availability); rarely works for the THIRD+ (substrate pool exhausted).

Filing as comment-only per this row's "let evidence accumulate over future sessions" disposition. The observation lives here for future-Otto archaeology; row update + rule refinement deferred.

docs/hygiene-history/ticks/2026/05/17/2300Z.md documents the arc cohesively; PR #4118's "Recursive forced-#6 self-documentation" insight captures the recursive shape.