fix: force install when node_modules missing

* feat: support close in bridge mode

* feat: WailsShutdown callback

Now handles proper shutdown through:
  * runtime.Window.Close()
  * Killing the main window
  * Ctrl-C

cmd/helpers.go

@@ -219,6 +219,15 @@ func InstallFrontendDeps(projectDir string, projectOptions *ProjectOptions, forc
 
 	const md5sumFile = "package.json.md5"
 
+	// If node_modules does not exist, force a rebuild.
+	nodeModulesPath, err := filepath.Abs(filepath.Join(".", "node_modules"))
+	if err != nil {
+		return err
+	}
+	if !fs.DirExists(nodeModulesPath) {
+		forceRebuild = true
+	}
+
 	// If we aren't forcing the install and the md5sum file exists
 	if !forceRebuild && fs.FileExists(md5sumFile) {
 		// Yes - read contents

cmd/version.go

@@ -1,4 +1,4 @@
 package cmd
 
 // Version - Wails version
-const Version = "v0.18.3"
+const Version = "v0.18.4"