fix(games): roll Umamusume's day at 15:00 UTC for every region

Umamusume Global resets once worldwide at 15:00 UTC (midnight JST); the app
used the regional default. Kept on the UTC calendar because the source's
dates are headed Availability (UTC). Source: Game-Time-Master.

Re-labels the game-day of some already-logged ticks.

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

test/daily.test.ts

@@ -508,6 +508,9 @@ describe("reset clocks, per server, as Game-Time-Master states them", () => {
     ["ba", "asia", "19:00", 9],
     ["ba", "america", "19:00", 9],
     ["ba", "europe", "19:00", 9],
+    ["uma", "asia", "15:00", 0],
+    ["uma", "america", "15:00", 0],
+    ["uma", "europe", "15:00", 0],
   ];
 
   for (const [game, region, utc, offset] of ROWS) {