Pipeline gap: the state machine refused `move_story(... target='backlog')`
from a Blocked story, leaving stuck items with no way to be parked while
waiting on dependent fixes — operators had to either Unblock (which
re-enters the active flow) or Archive (which loses the item).
Extend the existing Demote rule so `Blocked + Demote → Backlog` is a
legal transition, alongside the existing `Coding/Qa/Merge + Demote`.
Also update `map_stage_move_to_event` in agents/lifecycle.rs so the
chat/MCP `move_story` API recognises Blocked → backlog and routes it
through `PipelineEvent::Demote`.
Tests:
- `blocked_demote_returns_to_backlog` — happy path.
- `cannot_demote_from_done` / `cannot_demote_from_upcoming` — sanity
checks that the broadened rule does NOT permit Demote from
terminal or pre-triage stages.
Pattern follows 892 (MergeFailure → Done) and 893 (MergeFailure →
Coding) — pure transition.rs extension plus matching event mapping in
lifecycle.rs.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
dave
Timmy