Add create-plugin command and improve asset management

- Add new create-plugin command to generate plugins from starter template
- Add manifest name subcommand for template context
- Replace hardcoded asset paths with explicit file patterns in embed directive
- Refactor asset build system to use _setup.mk instead of setup.mk
- Update versioning to use pluginctl manifest id for APP_NAME
- Clean up Makefile by removing redundant bundle name definition

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

manifest.go

@@ -27,6 +27,8 @@ func RunManifestCommand(args []string, pluginPath string) error {
 	switch subcommand {
 	case "id":
 		fmt.Println(manifest.Id)
+	case "name":
+		fmt.Println(manifest.Name)
 	case "version":
 		fmt.Println(manifest.Version)
 	case "has_server":