Retiring an entity with status --archive is undocumented and leaves the move uncommittable

[clkao]

Problem

status --archive <slug> exists and works, but it is not listed in status --help's flag list, and after it runs the retirement cannot be committed through state commit:

spacedock status --workflow-dir <wf> --archive <slug>
  archived: <state>/_archive/<slug>

spacedock state commit <slug> --workflow-dir <wf>
  state commit: archived entity "<slug>" is dirty; archived scope is publish-only and
  will not stage or commit it:
  D  <slug>/index.md
  ?? _archive/<slug>/index.md

So the move only becomes durable with a manual path-scoped git add -A <slug> _archive/<slug> && git commit in the state checkout. The dangerous part is not the extra command, it is that the verb reports success while leaving the state checkout dirty; an FO that trusts the output walks away with an uncommitted retirement.

Reproduction

1. Entity at <slug>/index.md in a split-root state checkout (no origin).
2. spacedock status --workflow-dir <wf> --archive <slug> → prints archived: …/_archive/<slug>.
3. spacedock state commit <slug> --workflow-dir <wf> → prints the refusal above, exit 0, nothing committed.
4. git -C <state> status --porcelain → deletion of the active path plus untracked archive path.

Expected

List the verb in status --help, and make the retirement durable: either --archive commits the move itself, or state commit learns the archived scope. A success message should not be followed by silently uncommitted state.

Context

Observed on spacedock 0.28.0-pre2+dev (contract 3, pi host) on 2026-09-14, four retirements in one session (superseded, never-delivered entities). merge guard --rework correctly clears a pending terminal approval and the mod-block, but it does not archive, so retiring an entity always ends in this hand-rolled commit.