workout-tracker: add assets

From server log:
```sh
12:58PM WRN Not Found app=workout-tracker version=local sha=local module=webserver request.time="2024-09-15 12:58:39.875195 +0400 +04" request.method=GET request.host=localhost:8080 request.path=/assets/dist/htmx.min.js request.query="" request.params=map[*:/dist/htmx.min.js] request.route=/assets* request.ip=127.0.0.1 request.referer=http://localhost:8080/user/signin request.length=0 response.time="2024-09-15 12:58:39.875636 +0400 +04" response.latency=441.574µs response.status=404 response.length=0 error="map[code:404 internal:<nil> message:Not Found]"
```

pkgs/by-name/wo/workout-tracker/package.nix

@@ -1,13 +1,13 @@
 {
   lib,
   buildGoModule,
+  buildNpmPackage,
   fetchFromGitHub,
   nix-update-script,
   nixosTests,
   ...
 }:
-
-buildGoModule rec {
+let
   pname = "workout-tracker";
   version = "1.18.1";
 
@@ -18,8 +18,31 @@ buildGoModule rec {
     hash = "sha256-Sn6SOHrsp1ZgsPntc2+cmlAEPVBUrYv1vKLKAQvT9m4=";
   };
 
+  assets = buildNpmPackage {
+    pname = "${pname}-assets";
+    inherit version src;
+    npmDepsHash = "sha256-jHpvCMgjGvaAOfbslaIKfIRiPafScpn3WLnYamm+lbs=";
+    dontNpmBuild = true;
+    postPatch = ''
+      rm Makefile
+    '';
+    installPhase = ''
+      runHook preInstall
+      cp -r . "$out"
+      runHook postInstall
+    '';
+  };
+in
+buildGoModule rec {
+  inherit pname version src;
+
   vendorHash = null;
 
+  postPatch = ''
+    ln -s ${assets}/node_modules ./node_modules
+    make build-dist
+  '';
+
   passthru.updateScript = nix-update-script { };
 
   passthru.tests = {