Here is an excellent summary of a chicken first aid kit: https://www.backyardchickens.com/a/chicken-first-aid-kits-handy-and-essential-supplies-and-how-to-use-them
I would add duct tape (always useful for something) and a pet carrier.
Your calendar is already impressive! I hope you'll share when it's complete. I would add checking the first aid kit monthly to make sure nothing has leaked or expired. Plans for hot weather would also be helpful.