add cpucap to muede home config

homeConfigurations/muede/cpucap.nix

@@ -0,0 +1,25 @@
+{ lib, pkgs, ... }:
+let
+  # ./cpucap.sh goes into the store verbatim rather than through readFile or a
+  # generated wrapper script, because `cpucap --help` sed's the comment header
+  # back out of "$0" - only an unaltered copy of the file keeps that working.
+  cpucap = pkgs.runCommandLocal "cpucap" { nativeBuildInputs = [ pkgs.makeWrapper ]; } ''
+    install -Dm755 ${./cpucap.sh} $out/bin/cpucap
+    # Only line 1 changes, so the comment header --help prints stays put.
+    patchShebangs $out/bin/cpucap
+    wrapProgram $out/bin/cpucap \
+      --prefix PATH : ${
+        lib.makeBinPath [
+          pkgs.gawk
+          pkgs.gnused
+        ]
+      } \
+      --set CPUCAP_SELF $out/bin/cpucap
+  '';
+in
+{
+  # PATH is prefixed, not set: the script re-execs itself through
+  # /run/wrappers/bin/sudo for the writing subcommands, and sudo's own env
+  # handling plus the inherited system PATH have to survive that round trip.
+  home.packages = [ cpucap ];
+}