No badge for a year of hitting daily steps?

Nope. All badges are known so you can look at the available badges and see what you can be awarded for. There are no hidden badges that will popup.

You have been awarded with 12 x "10K a Day Challenge" and if your goal was set to 10k you also got 6 x "60-Day Goal Getter".

Shame - seems like a fairly obvious one to add to the pack 

Maybe because it would be too easy to reach. I've seen people getting tens of recurrent badges for reaching that goal several days in a row, but that's nuts. Just leave a fixed medium amount of steps and you can reach that for ten years

Change it to adjust automatically and keep it for a month. Now that's what I would call an achievement. My longest was maybe 12 days and the last day I've had to walk A LOT, even before going to bed, just because I was at 98% of the daily goal. Last day was more than twice the first, and I tried to walk not much more than each previous day.