race day tester + fixa open practice start och decoder-omritning

Nytt browser-test för start/paus/fortsätt/finish och byte till
nästa heat i kön, mot en simulerad decoder-socket (ingen riktig
AMMC-hårdvara). Hittade och fixade två buggar under vägen:

- Open Practice på sponsor/track-event kunde inte startas trots
  grönt ljus i förkontrollen (separat, striktare kontroll saknade
  samma undantag)
- Race Day-vyn ritades aldrig om när decodern anslöt/kopplades ner

Testramverket hanterar nu även native alert()/confirm()-dialoger
automatiskt, annars fryser en headless körning helt.

CHANGELOG.md

@@ -9,6 +9,12 @@ The application version is maintained in `package.json` and displayed in the adm
 ### Added
 
 - Personal mobile profiles show last successful data retrieval, stale-data and failed-update warnings, and a Retry button without replacing loaded statistics or active forms. Requests time out after 15 seconds and cannot overlap.
+- Browser coverage for Race Day start/pause/resume/finish and switching to the next queued heat, against a simulated decoder socket.
+
+### Fixed
+
+- Open Practice sessions on a sponsor (track-mode) event could show a ready/green Race Day preflight yet refuse to start, blocked by a stricter assignment check the preflight never warned about. Open Practice is now exempt from that check everywhere, matching the preflight.
+- The Race Day view did not refresh when the decoder connected, disconnected, or errored, so its Start button and preflight checklist could stay stale after a page load until something else triggered a re-render.
 
 ## 1.1.2 - 2026-09-08