chore(agents): stop installing retired skills

modules/agents/skills.nix

@@ -10,13 +10,10 @@ let
   user = config.user.name;
 
   # The skills installed globally, as derivations from the skills flake.
-  # wiki reads the personal Obsidian vault, and consume mines a source into it.
   # grill interviews the operator relentlessly to resolve a plan before building.
   # design-skill drafts and audits Agent Skills for structural predictability.
   # wayfinder, research, and prototype guide work from exploration through validation.
   skills = with inputs.skills.packages.${pkgs.stdenv.hostPlatform.system}; [
-    wiki
-    consume
     grill
     design-skill
     wayfinder