Move from PostMeal to PreMeal for New Meals

[amalnanavati]

The app's current mealState is stored in cookies, which persist after meals. Therefore, if one meal finishes and the user closes the app, when they re-open the app for the next meal it will still be in PostMeal. However, we want it to start in PreMeal.

One way of addressing it is to have the app store the timestamp of the last state transition in global state. Then, before rendering either App.jsx or Home.jsx (TBD -- the assignee of this issue can make an informed decision about which) the app checks whether it is in PoseMeal and more than some time (2 mins?) has passed between the last state changed time and the current time. If so it changes the mealState from PostMeal to PreMeal.

[amalnanavati]

Re-opening due to a bug where if the robot was on a moving state and then is closed for an hour, when it is re-opened it first calls the moving action, then cancels the moving action, and then renders the start feeding screen. This is a bug.

[amalnanavati]

As I was trying to address this, I was sometimes getting strange behavior where if we pause and then resume after a while, it wouldn't work because rosbridge can't find the action client. I'm not sure exactly what causes that, but it may have something to do with the fact that RobotMotion destroys the action server in the return of useEffect, even though it creates it with useMemo? Regardless, this collection of bugs is crucial to look into!

To recreate, pause a robot motion, then wait for a while (1.5 mins?) and resume, and it probably won't work.