Another one for floor first.

In our experience, it is better for the floors to be fitted first. We always ask for this for several reasons: Firstly, it would not give the best finish to cut the floor to fit around the parts of the cabientry that run to the floor, including the end panels and 'legs' of the cabientry in the above photo. Secondly, for long term maintenance - it can be problem to slide in/out appliances such as dishwashers and fridge freezers if they are not on a continuous floor, and some appliance brands insist that they sit on a solid floor for warranty purposes. Thirdly, it will future proof the kitchen if you ever want to change the layout of it. There are other reasons too, but all in all I would go with their advice and make sure it is properly protected. The only time it could be a problem is where the floor (e.g. timber) moves significantly after the cabientry has been fitted, but this should not be the case if the floor is well fitted. If your floor is tiled or is e.g. vinyl, there should be no movement.

We had our floor (LVT) put down before the kitchen was fitted.......

Joining those saying wall to wall. Have done many projects this way only, and will do it again.

Why would you not do it this way apart from to save money? If there is a leak, then you are more likely to notice it if the flooring is wall to wall too.

always floor first. It's easier to fit the kitchen and easier to fit the floor. The finished job will look way better

It is best to fit floor wall to wall for the reasons already stated by others. The end result is a much better finish.

Generally better to fit flooring last. Reduces likelihoods of damage to your floor and reduces flooring waste (paying for material you will not being seeing/using) but in your circumstances, with no kick boards, don't think you have much choice other than floor first but we endorse Jonathan's early comment… ensure the flooring is well protected during kitchen installation.