fix(herdr): support named primary sessions in lab tripwire

[Ikha14]

Summary

• let the isolated Herdr lab tripwire protect one exact recorded running primary session, including a named primary such as fm-wsl-minimal
• retain strict lab namespace, running-state, uniqueness, byte-identical snapshot, and immediate destructive ownership checks
• fix the focus-flash Part C fixture so sleep is a direct shell child rather than a grandchild hidden behind an asynchronously executed && list

Causal units

1. fix(herdr): protect recorded named primary in lab tests
2. test(herdr): keep persistent-child fixture direct

Validation

• timeout 600s tests/fm-herdr-lab.test.sh
• timeout 600s tests/fm-backend-herdr-focus-flash-e2e.test.sh
• bounded affected Herdr lab family: AFK injection/launch, autodetect, launcher workspace, presentation, prune safety, respawn idempotence, workspace-per-home, control, and session cleanup all passed
• timeout 600s bin/fm-doc-audience-check.sh
• timeout 600s bin/fm-lint.sh

No live primary Herdr lifecycle operation was performed.

[greptile-apps]

Confidence Score: 5/5

The PR appears safe to merge, with no concrete changed-code defect identified.

The named-primary resolution matches the documented safety contract, retains exact running-state and uniqueness checks, and the fixture change correctly creates the direct child required by the test.

_{Reviews (1): Last reviewed commit: "test(herdr): keep persistent-child fixtu..." | Re-trigger Greptile}

[kunchenguid]

Speaking as Kun's firstmate:

VISION (read current main 1231b6a in full). Inspected bin/fm-herdr-lab.sh, docs/herdr-backend.md, tests/fm-herdr-lab.test.sh, tests/herdr-test-safety.sh, tests/fm-backend-herdr-focus-flash-e2e.test.sh. Per-rule: strengthens a refusal path aligns (tripwire can protect an exact recorded running named primary such as fm-wsl-minimal, still refuses lab-namespace / missing / stopped / duplicate); lab isolation aligns; new capability as opt-in aligns for FM_HERDR_LAB_PRIMARY_SESSION. Mixed on the default path: when that var is unset, HERDR_SESSION is inherited (also re-exported from tests/herdr-test-safety.sh), and the jq match dropped the .default == true requirement in favor of exact name + running. Unset still falls back to literal default.

Class: corrective. Named-primary tripwire hole plus a test fixture so sleep is a direct shell child (cd / && sleep 3000 & → cd /; sleep 3000 &). Not default-behavior for production dispatch; this is the lab helper.

Security: none. No workflow files. Tripwire is safety-positive. Does not edit bin/backends/herdr.sh.

Overlap / HOLD: none that match the standing list. Not spawn/teardown, so hold-pair #2637/#2692 does not apply as an eligibility block the way lifecycle PRs do. #2792 overlap is herdr.sh-only and does not apply.

CI / NM: HEAD af6be6ebbf073d67ade2f3e42b46aa717f9c6048. MERGEABLE / UNSTABLE, ahead 2 / behind 0. Body has no no-mistakes-pipeline-attestation:v1. After this-pass approval, Require no-mistakes run 32607449835 completed FAILURE (body compliance) = NM red. CI run 32607449807 was queued at stamp. Greptile SUCCESS — not a gate.

Workflows approved this pass: 32607449807 (CI), 32607449835 (Require no-mistakes).

Land-eligible: NO (NM red without matching attestation; CI not green). Author needs a matching no-mistakes-pipeline-attestation:v1 for this HEAD. Captain-flag NOW: no.

[Ikha14]

Superseded by #2835, which preserves these fixes and pins the primary-session identity independently of mutable lab HERDR_SESSION.

[Ikha14]

Closing in favor of #2835.