feat(FN-3398): update desktop README with multi-project setup and troublesh

The merge lands Step 7 of FN-3398, adding documentation and delivery artifacts across the mobile and desktop packages with updated READMEs, mobile-specific docs, and architecture references.

Fusion-Task-Id: FN-3398

packages/dashboard/app/components/__tests__/NativeShellConnectionManager.test.tsx

@@ -0,0 +1,54 @@
+import { fireEvent, render, screen, waitFor } from "@testing-library/react";
+import { describe, expect, it, vi } from "vitest";
+import { NativeShellConnectionManager } from "../NativeShellConnectionManager";
+
+function createShellApi() {
+  return {
+    getState: vi.fn(),
+    listProfiles: vi.fn(),
+    saveProfile: vi.fn(async () => ({ id: "p1", name: "Prod", serverUrl: "https://fusion.example.com", createdAt: "", updatedAt: "" })),
+    deleteProfile: vi.fn(async () => undefined),
+    setActiveProfile: vi.fn(async () => ({ host: "mobile-shell", activeProfileId: "p1", profiles: [] })),
+    setDesktopMode: vi.fn(async () => ({ host: "desktop-shell", desktopMode: "remote", activeProfileId: null, profiles: [] })),
+    startQrScan: vi.fn(),
+    openConnectionManager: vi.fn(),
+    subscribe: vi.fn(() => () => undefined),
+  };
+}
+
+describe("NativeShellConnectionManager", () => {
+  it("switches desktop mode", async () => {
+    const shellApi = createShellApi();
+    render(
+      <NativeShellConnectionManager
+        open={true}
+        shellApi={shellApi}
+        shellState={{ host: "desktop-shell", desktopMode: "remote", activeProfileId: null, profiles: [] }}
+        onClose={vi.fn()}
+      />,
+    );
+
+    fireEvent.click(screen.getByText("Local"));
+    await waitFor(() => expect(shellApi.setDesktopMode).toHaveBeenCalledWith("local"));
+  });
+
+  it("edits and saves active profile", async () => {
+    const shellApi = createShellApi();
+    render(
+      <NativeShellConnectionManager
+        open={true}
+        shellApi={shellApi}
+        shellState={{ host: "mobile-shell", activeProfileId: "p1", profiles: [{ id: "p1", name: "Prod", serverUrl: "https://fusion.example.com", authToken: null, createdAt: "", updatedAt: "" }] }}
+        onClose={vi.fn()}
+      />,
+    );
+
+    fireEvent.change(screen.getByDisplayValue("https://fusion.example.com"), { target: { value: "https://next.example.com" } });
+    fireEvent.click(screen.getByText("Save"));
+
+    await waitFor(() => {
+      expect(shellApi.saveProfile).toHaveBeenCalled();
+      expect(shellApi.setActiveProfile).toHaveBeenCalledWith("p1");
+    });
+  });
+});