feat: refactor database access in analyticsStore to use executeAll and executeGet for improved query handling

drizzle/migrations/0004_analytics_perf_indexes.sql

@@ -0,0 +1,16 @@
+-- Add composite index for analytics queries: every analytics query filters by
+-- guild_id + created_at range + deleted_at IS NULL.
+-- This single index covers getHourlyStats, getTopicTrends, getUserLeaderboard,
+-- getModerationStats, getActiveChannelCount, and getTopViolators.
+CREATE INDEX IF NOT EXISTS "idx_messages_guild_created"
+  ON "messages" USING btree ("guild_id", "created_at");
+
+-- Covering index for analytics queries that also filter by ai_status
+-- (flagged/warn/clean counts). This speeds up the GROUP BY ai_status aggregates.
+CREATE INDEX IF NOT EXISTS "idx_messages_guild_status_created"
+  ON "messages" USING btree ("guild_id", "ai_status", "created_at");
+
+-- Composite index for channel-scoped analytics queries
+-- Covers channel_id + thread_id OR filters used when a specific channel is selected
+CREATE INDEX IF NOT EXISTS "idx_messages_guild_channel_created"
+  ON "messages" USING btree ("guild_id", "channel_id", "created_at");