A local building supply has plenty of the PB bullnose shelving --
about $8 for a 12" x 8'.

I'm still thinking to use my dado front support system for bracing.
I lay a back support down using 1x2s on the wall, and then I support
the front edge of the shelf about every 32" using 2x2" with dados at
the shelves. It works great for garage shelving using osb and 2x4s
(cut to size with a BS). In the closet -- well, we'll see -- hoping
to match the stain of door trim/floorboards and we'll see if the frong
"legs" are an eyesore.