Contract 6.36.5

The battles tools, after the Elixir Gym's third run on them (feedback #186-#190).

• battles_trends starts at from as given. It had moved from back to the Monday 00:00 UTC that starts its week while echoing the argument, so a days: 7 read counted 29 battles and a net of +29 where the window held 24 and -27, and a season read pooled ten hours of the season before. The first week is marked partial and says what it covers (#186).
• battles_trends labels each week's modes with the same fold as battles_query's mode_group, so event battles read event, not casual. The battles docs list trail under event, not casual, name event among the mode_group values and point at battles_query({ game_mode }) (#187).
• A raw battles_meta_decks or battles_meta_cards read over a segment says how many battles were outside the meta population (excluded.outside_meta) and why: event battles and decks the player did not choose. A player whose week was nearly all event play had read "considered 10, no decks" with nothing saying why (#188).
• players_timeline answers a named progress_key; every named key had failed with internal (#189).

Additive.