Fix retained attention queue echo projection

[yvette-carlisle]

Summary

• Deduplicate terminal Run Ledger attention from stale intake queue candidates when an issue still has both queue and needs-attention labels.
• Prefer retained Run Ledger attention ownership over queued-attention ownership for the retained worktree.
• Document the operator status contract for stale queue echo projection.

Verification

• cargo test -p decodex live_operator_status_snapshot_deduplicates_terminal_retained_attention_queue_echo --all-features -- --test-threads=1
• cargo test -p decodex live_operator_status_snapshot_surfaces_retained_partial_progress --all-features -- --test-threads=1
• cargo test -p decodex live_operator_status_snapshot_surfaces_stalled_retained_partial_progress --all-features -- --test-threads=1
• cargo test -p decodex local_status_summary_counts_terminal_history_needs_attention_without_queue_candidate --all-features -- --test-threads=1
• cargo make fmt
• cargo make lint-fix
• cargo make test
• git diff --check