How to add a climbable surface?

I’ve been following the Code3Arena tutorials, and I’m trying to complete #8, ladders. I’ve made all the modifications to the movement code, and edited .q3a/baseq3/pak0.pk3/scripts/common.shader to include

textures/common/climbclip
{
	qer_trans 0.40
	surfaceparm nolightmap
	surfaceparm nomarks
	surfaceparm nodraw
	surfaceparm nonsolid
	surfaceparm playerclip
	surfaceparm noimpact
	surfaceparm climb
}

…I opened up netradiant and created a map with brush textured with climbclip near a wall so I would have something to climb up. (I replaced ‘ladder’ with ‘climb’ all throughout my code changes, since I intend to expand on this later to climb other things besides ladders, and since the naming is consistent, this shouldn’t be a problem.)

When I load my map in quake, the wall is not nonsolid, and it is drawn, with a grey and white grid texture. I can change the texture to nodrawnonsolid, reload the map, and walk through it. I’ve already quintuple-checked that ioq3 is loading the correct pak files and I’ve make clean rebuilt the binaries, so I should definitely be running with all the correct modified files. I’m not sure what I’m borking here.

I would try taking out these first

surfaceparm nonsolid
surfaceparm playerclip
surfaceparm noimpact

Got some source code to test? Link to a commit?