tui3: a run's review checks are never drawn in the Tasks column (#1556 item 1)

[AbirAbbas]

What happened

The checks a run adds (check: <part>) exist in the plan but are never drawn in the Tasks side column, although internal/manual/chat/worker-harness.md says a run shows "its parts and their checks hanging under it". This is item 1 of #1556, split out because #1640 fixed items 2 and 4 and #1627 fixed item 3.

Replication

Deterministic (no model). A stubbed run with two parts and a review check: the plan database holds three tasks, and the side column draws two.

Where

• AddReviewCheck in internal/plandb/store.go does not give the check its parent's chat tag, the way Add does.
• The Tasks column's plan listing filters by that tag, so the check is dropped.
• The two-line fix changes what runsummary.go and runask.go count, so those have to be checked in the same change.

The fix

A review check carries its parent's chat tag, so it is drawn under its part. Run summaries count parts and checks the way the manual describes.

Acceptance

• Unit (tui3): a run with two parts and one check draws the check under its part.
• Unit: the run summary's counts are unchanged for parts, and name checks separately if they are counted at all.