feat(webui): polish agent output and app discovery

webui/src/tests/useLogoFallback.test.tsx

@@ -7,15 +7,13 @@ import {
 } from "@/hooks/useLogoFallback";
 
 function TestLogo({ urls }: { urls: string[] }) {
-  const { logoUrl, onLogoError, onLogoLoad } = useLogoFallback(urls);
+  const { logoUrl, logoLoaded, onLogoError, onLogoLoad } = useLogoFallback(urls);
   if (!logoUrl) return <span>No logo</span>;
   return (
-    <img
-      src={logoUrl}
-      alt="Logo"
-      onLoad={onLogoLoad}
-      onError={onLogoError}
-    />
+    <>
+      <span>{logoLoaded ? "Loaded" : "Loading"}</span>
+      <img src={logoUrl} alt="Logo" onLoad={onLogoLoad} onError={onLogoError} />
+    </>
   );
 }
 
@@ -32,15 +30,18 @@ describe("useLogoFallback", () => {
     const first = render(<TestLogo urls={urls} />);
 
     expect(screen.getByRole("img", { name: "Logo" })).toHaveAttribute("src", urls[0]);
+    expect(screen.getByText("Loading")).toBeInTheDocument();
 
     fireEvent.error(screen.getByRole("img", { name: "Logo" }));
     expect(screen.getByRole("img", { name: "Logo" })).toHaveAttribute("src", urls[1]);
 
     fireEvent.load(screen.getByRole("img", { name: "Logo" }));
+    expect(screen.getByText("Loaded")).toBeInTheDocument();
     first.unmount();
     render(<TestLogo urls={urls} />);
 
     expect(screen.getByRole("img", { name: "Logo" })).toHaveAttribute("src", urls[1]);
+    expect(screen.getByText("Loaded")).toBeInTheDocument();
   });
 
   it("returns no logo once every candidate failed", () => {