Add the desktop shortcut and the gsettings schema to the fitnesstrax installation

fitnesstrax/app/override.nix

@@ -3,6 +3,12 @@ attrs: {
     nativeBuildInputs = gtkNativeInputs;
     postInstall = ''
         install -Dt $out/share/applications resources/fitnesstrax.desktop
-        install -Dt $out/share/glib-2.0/schemas resources/com.luminescent-dreams.fitnesstrax.gschema.xml
+        install -Dt $out/gsettings-schemas/${attrs.crateName}-${attrs.version}/glib-2.0/schemas resources/com.luminescent-dreams.fitnesstrax.gschema.xml
+        glib-compile-schemas $out/gsettings-schemas/${attrs.crateName}-${attrs.version}/glib-2.0/schemas
+    '';
+    preFixup = ''
+        gappsWrapperArgs+=(
+            --prefix XDG_DATA_DIRS : $out/gsettings-schemas/${attrs.crateName}-${attrs.version}
+        )
     '';
 }

flake.nix

@@ -58,6 +58,7 @@
             pkgs.pkg-config
             pkgs.gtk4
             pkgs.libadwaita
+            pkgs.wrapGAppsHook4
           ];
 
           cargoOverrides = pkgs: pkgs.buildRustCrate.override {