feat(layouts): optional min/max lap time per track layout for practice

Each layout can carry its own lap window (set on creation, editable in
Settings, saved from Race Day during practice). Open/Free practice on
that layout uses it; races always keep the event's values.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "rc-racecore",
-  "version": "1.30.0",
+  "version": "1.31.0",
   "private": true,
   "description": "RC RaceCore live timing and race control with AMMC ingest and SQLite persistence",
   "engines": {