feat(channelserver): add daily noon resets for gacha stepup and guild RP

Gacha stepup progress now resets when queried after the most recent
noon boundary, using a new created_at column on gacha_stepup.

Guild member rp_today rolls into rp_yesterday lazily when members are
enumerated after noon, using a new rp_reset_at column on guilds.

Both follow the established lazy-reset pattern from the cafe handler.

schemas/patch-schema/30-daily-resets.sql

@@ -0,0 +1,6 @@
+BEGIN;
+ALTER TABLE IF EXISTS public.gacha_stepup
+    ADD COLUMN IF NOT EXISTS created_at TIMESTAMP WITH TIME ZONE DEFAULT now();
+ALTER TABLE IF EXISTS public.guilds
+    ADD COLUMN IF NOT EXISTS rp_reset_at TIMESTAMP WITH TIME ZONE;
+END;