Make custom swaylock wrapper own derivation

Hopefully fix issues with swayidle not being able to find wrapped
script by passing derivation directly

programs/sway/swayidle/default.nix

@@ -1,11 +1,19 @@
-{...}: {
+{
+  config,
+  pkgs,
+  ...
+}: {
   imports = [../swaylock/default.nix];
-  services.swayidle = {
+  services.swayidle = let
+    swaylockfx =
+      pkgs.callPackage ../swaylock/swaylockfx.nix
+      {swaylock-effects = config.programs.swaylock.package;};
+  in {
     enable = true;
     timeouts = [
       {
         timeout = 60 * 15; # 15 minutes
-        command = "swaylockfx";
+        command = "${swaylockfx}/bin/swaylockfx";
       }
     ];
   };

programs/sway/swaylock/default.nix

@@ -5,8 +5,8 @@
   ...
 }: {
   home.packages = with pkgs; [
-    (writeShellScriptBin "swaylockfx"
-      "${config.programs.swaylock.package}/bin/swaylock --screenshots --clock --indicator --grace-no-mouse")
+    (callPackage ./swaylockfx.nix
+      {swaylock-effects = config.programs.swaylock.package;})
   ];
   programs.swaylock = {
     enable = true;

programs/sway/swaylock/swaylockfx.nix

@@ -0,0 +1,6 @@
+{
+  writeShellScriptBin,
+  swaylock-effects,
+  ...
+}:
+writeShellScriptBin "swaylockfx" "${swaylock-effects}/bin/swaylock --screenshots --clock --indicator --grace-no-mouse"