pm duplicates silently accepts --status all and scans zero items instead of rejecting it or selecting all statuses #930

Summary

On @unbrained/pm-cli 2026.8.7, pm duplicates --status all exits successfully but silently scans zero items. The equivalent unfiltered command scans the complete tracker. This creates a false clean duplicate-audit result in the natural all-status workflow.

This is a core command issue and reproduces with project extensions enabled or disabled.

Reproduction

In a workspace containing 85 items across lifecycle statuses:

$ pm --version
2026.8.7

$ pm duplicates --status all --threshold 0.82 --limit 100
count: 0
cost:
  item_count: 0
  candidate_pairs: 0
  scored_pairs: 0

$ pm duplicates --threshold 0.82 --limit 100
count: 0
cost:
  item_count: 85
  candidate_pairs: 1490
  scored_pairs: 1490

$ pm duplicates --status open,in_progress,blocked,closed,canceled,draft --threshold 0.82 --limit 100
count: 0
cost:
  item_count: 85
  candidate_pairs: 1490
  scored_pairs: 1490

The result cluster count happens to be zero in this workspace, but the cost.item_count evidence shows that the --status all invocation did not inspect the tracker.

Contract inconsistency

pm contracts --command duplicates --json describes status as project-configurable and states:

Unknown statuses are rejected at runtime with a did-you-mean hint.

all is not one of this workspace's configured statuses, yet it is accepted and treated as a literal filter that matches nothing. By comparison, pm list --status all explicitly supports the natural all-status spelling.

Expected behavior

Either behavior would be safe and internally consistent:

1. Treat --status all as the explicit all-status alias, matching pm list; or
2. Reject all as an unknown status with a non-zero exit and remediation to omit --status or enumerate configured statuses.

The current exit-0 empty scan is unsafe because it looks exactly like a successful full-tracker duplicate check.

Duplicate search

Searched all open and closed issues for:

• pm duplicates --status all
• duplicates unknown status
• duplicates status filter
• zero items duplicates

Reviewed adjacent duplicate-command issues #705, #709, #739, #830, and #871. None covers silent zero-item scans for the all status value.