archive-threadlisted

# Archive Thread Archive a thread by relocating its folder from the active `docs/threads/` listing into `docs/threads/archive/`. This is the act that ends a thread's active lifecycle: once its folder sits under `archive/`, the thread is no longer live work. Archiving happens on **explicit user intent only**. Never scan for archivable threads on your own initiative, and run **no completion checks of any kind** — you do not inspect any status or report to decide whether the thread "deserves" archival. If the user asks to archive a thread, that intent is the whole authorization. ## Resolve the target thread The user names the thread to archive (by slug or by path). A thread root is a folder directly under `docs/threads/` named with a UTC-timestamp slug (e.g. `docs/threads/250522143000Z-my-feature/`). If which thread the user means is ambiguous, ASK — never silently pick one. `docs/threads/archive/` is the archive container, not a thread; ignore it when resolving a target. ## Pre-move inspection Before moving, look inside the target thread for three workspace folders that hold unfinished state: - **`.pending-decisions/`** — bundles of decisions awaiting a human. - **`.pending-reviews/`** — recorded review findings not yet acted on. - **`.implementation-runs/`** — interrupted or abandoned run state. If any of these is non-empty, **name what it contains** — the bundle titles or headers in `.pending-decisions/` and `.pending-reviews/`, the interrupted run identifiers in `.im