cookie data grows without bound

[s-edwards]

As a logged-in user practices exercises in the gym, they get added to the browser cookie value ... I'm guessing as part of transient session state stored in the cookie params. However, more practice with different exercises just causes this to grow, until the cookie size exceeds the limit configured for the application and requests start failing due to a cookie size too long, making the request header too long.

[s-edwards]

Fixed in 78c318c.