Daily snapshots are keyed by the game day

A player's daily snapshot was filed under the UTC calendar date it was taken on, while war days, the season roll and every clan's policy day run on the 10:00 UTC grid: the snapshot taken in the hour before a season rolls (Monday 09:00 UTC) sat on the new season's Monday, and a snapshot at 03:00 UTC was a different day from the war day it was played in. Every snapshot row now sits on its game day, the date whose 10:00 UTC start it follows; where a day's early-morning poll and the previous day's late one landed on the same game day, the later observation is the row, which is the rule the table always had. players_timeline points, players_summary.trophies_as_of and clans_participation's donation columns read the same way with the corrected days; no tool changes shape.