test: drop two double casts from the new App case (#2217)

Copilot, and the repo's own rule against an unjustified `as unknown as`.
The `useServers` cast was the more useful catch: removing it surfaced
that the mock omitted `reorderServers` and `importSource`, so App code
calling either would have read `undefined` with this test still passing
type-check. The full result shape is supplied instead, matching the
`mockServersWith` helper above.

The client cast becomes an intersection — the instances are already typed
`EventTarget`, so naming the test-only spy on top of that expresses what
is needed without erasing the rest.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VGbw6TezNWnXZSCSp7sqb4
Signed-off-by: cliffhall <cliff@futurescale.com>

clients/web/src/App.test.tsx

@@ -4258,7 +4258,9 @@ describe("App dedupes concurrent OAuth clears that share a storage key (#2217)",
       updateServer: updateServerSpy,
       updateServerSettings: updateServerSettingsSpy,
       removeServer: vi.fn(),
-    } as unknown as ReturnType<typeof useServers>);
+      reorderServers: vi.fn(),
+      importSource: vi.fn().mockResolvedValue({ servers: {} }),
+    });
   });
 
   afterEach(() => {
@@ -4299,7 +4301,9 @@ describe("App dedupes concurrent OAuth clears that share a storage key (#2217)",
 
       await user.click(screen.getByText("connect"));
       await waitFor(() => expect(clientInstances).toHaveLength(1));
-      const client = clientInstances[0] as unknown as {
+      // The instances are typed `EventTarget`; an intersection names the
+      // test-only spy without erasing that (Copilot).
+      const client = clientInstances[0] as EventTarget & {
         clearOAuthTokens: ReturnType<typeof vi.fn>;
       };