Fix Three Defects in the Handoff and Burndown Skills Raised on a Downstream Carry

[ptr727]

Raised by CodeRabbit and Qodo on ptr727/PlexCleaner#999, a resync carrying .github/skills/** byte-identical from hub main at 4566946. Each was verified against the hub's .agents/skills/ source at that commit. The fix belongs here, followed by a regeneration, so the downstream copy is left as carried. No open issue or PR covered these when this was filed.

A. Handoff commands shown without the required --repo

scripts/handoff.py makes --repo required with no default (around line 976). Several command forms in the skills leave it out:

• .agents/skills/unattended-handoff/SKILL.md:153: handoff.py chain --track "auto-<issue>" --limit 1. Line 154 turns "any other refusal" into STOP, so a picker that runs this as written stops on the argparse refusal instead of answering the eligibility question.
• .agents/skills/unattended-handoff/SKILL.md:180 (handoff.py new) and :189 (handoff.py resume). The worker step has no pointer to session-handoff "Running the Chain", which is the only place that says every subcommand takes --repo.
• .agents/skills/session-handoff/SKILL.md:146 and .agents/skills/unattended-handoff/SKILL.md:190: gh issue view "<n>" --comments without --repo. A session running from the hub checkout it needs for handoff.py reads the hub's issue <n> instead of the target repository's.

Expected: every documented invocation carries --repo "<owner>/<repo>", or states once, where the command appears, that it does.

B. Handoff pickers rank a list truncated at 100

.agents/skills/unattended-handoff/SKILL.md:167 and .agents/skills/session-handoff/SKILL.md:172 read open handoffs with gh issue list --label handoff --state open --limit 100 and then pick oldest-first or newest-update. Past 100 open handoffs, a candidate outside the window is invisible, so the picker can choose the wrong lane or return NONE while eligible work remains. This is far off in practice. Expected: paginate, or detect a full page and refuse rather than rank a truncated list.

C. backlog-burndown gives no precedence for an issue labeled both handoff and blocked

.agents/skills/backlog-burndown/SKILL.md:112-119: the handoff rule excludes an issue from "every count", while the blocked rule counts it while its blocker stands. The fleet's own parking flow (unattended-handoff) puts blocked on a handoff issue, so both rules apply, and the backlog count can be off by one per parked lane. Expected: state which rule controls.

Declined on the PR, recorded for context

• Qodo on GOVERNANCE.md "Workflow YAML Conventions": the claim that $/ is not a valid self-repository uses: form is false. The hub uses it at .github/workflows/build-release-task.yml:115.
• CodeRabbit on the .github/copilot-instructions.md coverage carry-forward: the review itself must still cover the current head. Only the file-count coverage statement carries forward, and only while the changed-file set is identical (see A ccr-overview-v2 Round States No File Coverage, and the Exit-45 Remedy Cannot Clear It #1692).
• CodeRabbit on check-this-repo flagging a detached checkout: working as designed, since a detached checkout cannot track main.
• CodeRabbit on unattended-handoff retained state omitting <owner>/<repo>: a wording preference, since the value is fixed for the run and every brief consumes it.
• CodeRabbit on check-jsonschema@latest in workflow-ci-contract: fleet policy. GOVERNANCE.md "Running the Linters Locally" floats lint tools deliberately. Reopening that is a policy call for the maintainer.

[ptr727]

The same carry was raised again on the promotion PR ptr727/PlexCleaner#1000 and re-verified against hub main at 4566946.

• A and B were raised again. Open hub PR Promote the C# Coverage Report Check, Archived-Repository Exemption, and Overnight Fixes to Main #1850 (develop -> main) adds --repo "<owner>/<repo>" to the handoff.py chain, new, and resume forms and to gh issue list and gh issue view, and it adds a truncation note for --limit. Those changes should close A and B once Promote the C# Coverage Report Check, Archived-Repository Exemption, and Overnight Fixes to Main #1850 is promoted. C is still open.

Two new defects:

D. .github/copilot-instructions.md blocks the merge on any body-only finding, even an answered one

Hub .github/copilot-instructions.md:31 lists "an unresolved thread, or a body-only finding" as merge blockers and does not say "unanswered". The Merge Gate in .agents/skills/pr-review-conduct/SKILL.md:69-71 closes a body finding once it is "investigated and answered". Read literally, :31 keeps a declined body-only finding on the head blocking the merge forever. Expected: :31 says an unanswered body-only finding, matching the Merge Gate.

E. repo-worktree's standalone-clone fallback has no way to continue an existing branch

.agents/skills/repo-worktree/SKILL.md:134-137 and :162-167: the fallback only runs fetch origin develop and switch -c <task-branch> origin/develop. The continuation form at :174-178 only works for a worktree. So a continuation that has to use the fallback forks a fresh branch from develop. A prior task branch that exists only in the base clone, or only on the remote, is never checked out, and the work would continue without its earlier commits. Expected: a fallback continuation step that fetches and checks out the existing task branch, local or remote, before falling back to creating one.

Also declined on #1000, recorded for context

• drive-pr verify-then-delete race: real, but by design under the --force-with-lease ban and already tracked by Decide whether merge-and-release's branch cleanup should use compare-and-delete #946.
• backlog-burndown direct-commit references: already required at :404-408.
• comment-and-doc-style pointer to "Running the Linters Locally": the pointer says the section is hub-only and names the hub's GOVERNANCE.md.
• d-guarantees.md D1 include: it matches WORKFLOW.md exactly, and build_dist.py --check is clean. The conflict is PlexCleaner's own divergence, filed in PlexCleaner.
• unattended-handoff local-work exclusion: eligibility reads only durable claims, by design.