function createHost() {
  return {
    basePath: "",
    client: { stop: vi.fn() },
    connectGeneration: 0,  // hand-set — matches type contract
    ...
  };
}

// ui/src/ui/app.smoke.test.ts
import "./app.ts"; // registers the custom element
import { describe, it, expect } from "vitest";

describe("RemoteClawApp instance — host interface compliance", () => {
  it("initializes every required LifecycleHost field", () => {
    const el = document.createElement("remoteclaw-app") as any;
    const required = [
      "basePath", "connectGeneration", "tab", "assistantName",
      "assistantAvatar", "assistantAgentId", "serverVersion",
      "chatHasAutoScrolled", "chatManualRefreshInFlight", "chatLoading",
      "chatMessages", "chatToolMessages", "chatStream",
      "logsAutoFollow", "logsAtBottom", "logsEntries",
      "popStateHandler", "topbarObserver",
    ];
    for (const field of required) {
      expect(el[field], `missing LifecycleHost field: ${field}`).not.toBeUndefined();
    }
  });

  it("initializes every required GatewayHost field", () => {
    const el = document.createElement("remoteclaw-app") as any;
    const required = [
      "settings", "password", "clientInstanceId", "client", "connected",
      "hello", "lastError", "lastErrorCode", "eventLogBuffer", "eventLog",
      "tab", "presenceEntries", "presenceError", "presenceStatus",
      "agentsLoading", "agentsList", "agentsError",
      "toolsCatalogLoading", "toolsCatalogError", "toolsCatalogResult",
      "debugHealth", "assistantName", "assistantAvatar", "assistantAgentId",
      "serverVersion", "sessionKey", "chatRunId", "refreshSessionsAfterChat",
      "execApprovalQueue", "execApprovalError", "updateAvailable",
    ];
    for (const field of required) {
      expect(el[field], `missing GatewayHost field: ${field}`).not.toBeUndefined();
    }
  });

  it("initializes every required ToolStreamHost field", () => {
    const el = document.createElement("remoteclaw-app") as any;
    const required = [
      "sessionKey", "chatRunId", "chatStream", "chatStreamStartedAt",
      "chatStreamSegments", "toolStreamById", "toolStreamOrder",
      "chatToolMessages", "toolStreamSyncTimer",
    ];
    for (const field of required) {
      expect(el[field], `missing ToolStreamHost field: ${field}`).not.toBeUndefined();
    }
  });
});