Semi-aggressive plant suggestion?

I live North of Boston (Zone 5).  Soil is mostly sand + rocks, so I have trouble growing anything.  One hillside in particular is probably old debris, and is more than 50% rocks, and has a fair amount of shade.  One the sunnier portions, Forsythia & Daylilies do very well.  On shadier parts, only Greater Celandine (Chelidonium majus), oriental bittersweet and Garlic Mustard thrive.  Oh, and a groundhog.

I would like something robust, even lightly aggressive, which can thrive and spread...but not so aggressive I regret it!

In order of preference, I'd like it to be:
  Edible
  Medicinal
  Beautiful
  Cuttable for compost
  A distraction to keep the groundhog away from more valued stuff!

I do want to be able to walk on the hill.

I wonder about mint (I do want some varieties somewhere, but have been warned in strong terms!

Got any great ideas?
thanks!

Go to a similar location which is untended, and growing lots of stuff. Bring home a bucket full of dirt and spread it around. Or bring home a few of the plant species for planting at your place.

Lemon Balm is a mint that is not very aggressive.  Though in your situation any mint would probably work if you can water it.

Groundhogs don't like smelly plants so lavender, rosemary, and chives planted on the perimeter of your planting area might help.

Edible: plant lettuce
Medicinal: Lavender, rosemary
Beautiful: butterfly weed
Cuttable for compost: comphrey
A distraction to keep the groundhog away from more valued stuff: listed above

I am looking forward to the other suggestions.

Here are some:

https://www.thespruce.com/how-to-deal-with-plant-thugs-1403542

Hi Michael, like Anne says, lemon balm is a prolific plant (self-seeding) and edible, mountain mint is also less aggressive than other mints. Both are tall, and it's fun to walk next to them and brush into and get a whiff of mint or lemon.

Vinca (periwinkle) is low-growing creeping groundcover, with nice foliage and pretty periwinkle color flowers, seems to block out other stuff, does well in shade.
Lily of the valley (sort of aggressively spready?) also does well in shade.
Daylilies are edible (haven't tried myself) also do a decent job of taking up space.

Rhubarb? can grow quite large but it is a heavy feeder, so you'd need to amend that area. It would be good in a sunny spot.

If you have deer, I'd stay away from hostas.

Spring flowers like daffodils/narcissus, hyacinth, squill, snowdrops, tulip, would add color and interest, but they die back in the summer so something else to succeed them would be ideal.
Alliums bloom a bit later, and aren't bother by pests so much, edible ones like chive, garlic chive, garlic, Egyptian (walking) onions would be great.

I'm going to send you a Purple Moosage, we're maybe 20 minutes apart? I may have some of these to offer right now! before I trample them with a tractor!!