Fix various off-by-one errors in statistics time ranges (#40193)

Co-authored-by: Shlee <github@shl.ee>

app/controllers/admin/dashboard_controller.rb

@@ -12,7 +12,7 @@ module Admin
       @pending_tags_count    = pending_tags.async_count
       @pending_users_count   = User.pending.async_count
       @system_checks         = Admin::SystemCheck.perform(current_user)
-      @time_period           = (29.days.ago.to_date...Time.now.utc.to_date)
+      @time_period           = (29.days.ago.to_date..Time.now.utc.to_date)
     end
 
     private