feat: scaffold yonexus server plugin

plugin/index.ts

@@ -0,0 +1,28 @@
+export interface YonexusServerPluginManifest {
+  readonly name: "Yonexus.Server";
+  readonly version: string;
+  readonly description: string;
+}
+
+export interface YonexusServerPluginRuntime {
+  readonly hooks: readonly [];
+  readonly commands: readonly [];
+  readonly tools: readonly [];
+}
+
+const manifest: YonexusServerPluginManifest = {
+  name: "Yonexus.Server",
+  version: "0.1.0",
+  description: "Yonexus central hub plugin for cross-instance OpenClaw communication"
+};
+
+export function createYonexusServerPlugin(): YonexusServerPluginRuntime {
+  return {
+    hooks: [],
+    commands: [],
+    tools: []
+  };
+}
+
+export default createYonexusServerPlugin;
+export { manifest };