_close_and_draw set round_.status = "closing" but then immediately
overwrote it in memory with "closed" (no participants) or "drawing"
(with participants) before the first session.commit() — so "closing"
was never actually written to the database, only ever visible in the
ORM object's transient in-memory state. GET /rounds/current (and the
frontend's "in chiusura" label) could never observe it.
Committing right after setting "closing"/closed_at, before querying
participants, makes it a real, briefly-observable state like the
others in the round lifecycle.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>