feat(FN-3332): add droid runtime plugin with event bridge and process manag

The merge delivers a new `fusion-plugin-droid-runtime` plugin providing a full MCP server and runtime adapter for droid-based agents, with event bridging, process management, tool mapping, and a prompt builder. It also adds agent delegation and org hierarchy tools to the pi extension, while fixing a

Fusion-Task-Id: FN-3332

plugins/fusion-plugin-droid-runtime/src/__tests__/index.test.ts

@@ -0,0 +1,25 @@
+import { describe, expect, it } from "vitest";
+import { validatePluginManifest } from "@fusion/plugin-sdk";
+import plugin, { droidRuntimeMetadata, DROID_RUNTIME_ID } from "../index.js";
+
+describe("droid runtime plugin index", () => {
+  it("exports expected manifest/runtime metadata", () => {
+    expect(plugin.manifest.id).toBe("fusion-plugin-droid-runtime");
+    expect(droidRuntimeMetadata.runtimeId).toBe("droid");
+    expect(DROID_RUNTIME_ID).toBe("droid");
+  });
+
+  it("registers required ui slots", () => {
+    const slots = plugin.uiSlots?.map((s) => s.slotId) ?? [];
+    expect(slots).toEqual(expect.arrayContaining([
+      "settings-provider-card",
+      "onboarding-provider-card",
+      "onboarding-setup-help",
+      "post-onboarding-recommendation",
+    ]));
+  });
+
+  it("has a valid manifest", () => {
+    expect(() => validatePluginManifest(plugin.manifest)).not.toThrow();
+  });
+});