docs(handoff): rank 3 slice 2 MERGED as #1406 — and the closing condition is still only HALF met

[ZacxDev]

Records the outcome of rank 3 slice 2 and supersedes devrc #1417, which is being closed rather than merged — see below.

Slice 2 is merged (#1406, squash 9300f234), verified by content, never by ancestry — a squash makes merge-base --is-ancestor false forever, so that check reads as "not merged" and is wrong.

🔴 The closing condition is only half met, and the doc now says so. readlink -f ~/.local/bin/cairn still resolves to /home/zach/workspace/devrc/scripts/cairn. The binary becomes a store path at home-manager switch, not at merge, and the laptop is a second, independent switch. Merged ≠ deployed ≠ verified.

Three audit rounds, and rounds 2 and 3 both found real defects — in the previous round's fixes, not in the payload. The ladder did not end on a clean round; it ended on an operator call, with five 🟡s recorded open-by-decision on #1406. That distinction is written down, because a report that ends on an escape hatch is otherwise indistinguishable from one that converged.

New investigation blocks:

1. The Tekton red is attributed to the TIER, not the tree — by a control, not by sampling. PR docs(handoff): #1406 round-1 audit fixes are COMMITTED, and the branch now carries a TRUE merged tree #1417 failed on the same assertion, and docs(handoff): #1406 round-1 audit fixes are COMMITTED, and the branch now carries a TRUE merged tree #1417 changes exactly one markdown file. A docs-only diff cannot break a server-API test. Root cause remains unknown and the doc says so; the runs are pruned.
2. Three reds only the MERGED tree could find. A seam ledger correctly refusing a new router; a repo-wide shebang scan; and a guard structurally incapable of passing in the sandbox tier — it asserted on stdout, which holds only where a cache root exists. Re-measured at two points and the killing mutant re-verified at both.
3. The mutation evidence from rounds 1 and 3, including a mutant that survived round 3's first battery because it was unreachable, recorded rather than hidden.

⚠ Why #1417 is closed, not merged: four commits touched this doc on main while it sat open — including c756efe0, which made the same correction #1417 existed for. Merging it would have replaced 1,189 lines with 1,129 and dropped other sessions' newer content. Its unique content is re-landed here on top of current main. A docs PR left open across a busy day is a stale-base hazard.

🤖 Generated with Claude Code

https://claude.ai/code/session_01NTRPN6dhkdf8kZJch3mne5