bug(unic-archon-dlc, upstream: Archon): archon complete <branch> --force deletes the branch on origin, silently #491

Observed

Archon CLI v0.8.0, linux-arm64, Azure DevOps remote (DXP-DesignSystem). Closing run 3: git ls-remote --heads origin listed 11 heads before archon complete archon/task-unic-dlc-build-1789577744739 --force and 10 after; the only missing line was that branch. The command printed env_removed, Completed: <branch>, Complete: 1 completed, 0 failed, 0 not found and nothing about the remote, three times over for three branches. The nine build commits survived only because the session pinned refs/rescue/<name> before gc; the branch was pushed back from that ref.

docs/agents/unic-archon-dlc.md:285 documents complete degrading its gh pr list check to a warning on an Azure DevOps remote. It does not say the command deletes the remote branch, and no warning printed.

Why it matters

"Abandon the PR, keep the branch" is the stream's rule for every measured run, and archon complete breaks it without saying so. Runs 1 and 2 survive only on origin.

Evidence

• Findings register, § "G. What run 3 taught about the instrument", row G1: https://github.com/unic/unic-agents-plugins/blob/bcf688a/docs/research/2026-08-31-dlc-run-2-findings.md
• Run record and harvested artefacts: ~/Desktop/run3-parked/ on the maintainer's machine (run record § the close; three origin snapshots quoted in it)
• Dispatch record: #457 from comment 5698289748 down

Not decided

• Upstream: file on Archon, or document and avoid complete on pushed branches (git worktree remove + git branch -D instead).
• Consumer doc row: pin refs/rescue/* before any Archon cleanup verb; measure with git ls-remote --heads origin before and after.

Filed 2026-09-17 by wayfinder-orchestrator-10 from run 3's measurements. needs-specs: grill before dispatch.