Remove benchmark skill

flake.nix

@@ -90,26 +90,18 @@
               inherit pkgs mkSkill mkSkillsShellHook;
             };
 
-            # Proves the benchmark skill's deterministic core at its single seam:
-            # it feeds committed fixtures to the core and asserts the metrics, the
-            # Efficacy verdict, and the rendered report.
-            benchmark-core = import ./checks/benchmark-core.nix {
-              inherit pkgs;
-            };
+
           };
 
           # A working shell for developing skills in this repo.
-          # Python runs the benchmark core, while gitea-axi backs its project skill.
-          # Both project skills are placed into ./.agents/skills/ on entry, with
-          # ./.claude/skills as a compatibility symlink.
+          # The gitea-axi project skill is placed into ./.agents/skills/ on entry,
+          # with ./.claude/skills as a compatibility symlink.
           devShells.default = pkgs.mkShell {
             packages = [
-              pkgs.python3
               gitea-axi.packages.${system}.gitea-axi
             ];
             shellHook = mkSkillsShellHook [
               gitea-axi.packages.${system}.gitea-axi-skill
-              (skillPackages pkgs).benchmark-skill
             ];
           };
         }