add webview threaded api

pkgs/webview-ui/flake-module.nix

@@ -0,0 +1,31 @@
+{ inputs, ... }:
+{
+  perSystem =
+    { system, pkgs, config, ... }:
+    let 
+      node_modules-dev = config.packages.webview-ui.prepared-dev;
+    in
+    {
+      packages.webview-ui = inputs.dream2nix.lib.evalModules {
+        packageSets.nixpkgs = inputs.dream2nix.inputs.nixpkgs.legacyPackages.${system};
+        modules = [
+          ./default.nix
+        ];
+      };
+      devShells.webview-ui = pkgs.mkShell {
+        inputsFrom = [ config.packages.webview-ui.out ];
+        shellHook = ''
+          ID=${node_modules-dev}
+          currID=$(cat .dream2nix/.node_modules_id 2> /dev/null)
+
+          mkdir -p .dream2nix
+          if [[ "$ID" != "$currID" || ! -d "app/node_modules"  ]];
+          then
+            ${pkgs.rsync}/bin/rsync -a --chmod=ug+w  --delete ${node_modules-dev}/node_modules/ ./app/node_modules/
+            echo -n $ID > .dream2nix/.node_modules_id
+            echo "Ok: node_modules updated"
+          fi
+        '';
+      };
+    };
+}