fix(status-bar): running / need-you count only the viewer's own sessions

An admin's status bar and the Dashboard's Needs-you strip counted every
user's waiting sessions; both now ask GET /api/sessions with mine=1, like
Today's spend already did.

client/src/components/__tests__/StatusBar.test.tsx

@@ -183,6 +183,9 @@ describe("StatusBar", () => {
     );
     await screen.findByText("1 need you");
     expect(screen.getByTestId("status-bar-counts").textContent).toBe("2 running · 1 need you");
+    // The user's OWN sessions, even for an admin who sees every user's rows.
+    for (const [p] of vi.mocked(api.sessions.list).mock.calls)
+      expect(p).toMatchObject({ mine: true });
     await user.click(conn);
     expect(onConnectionClick).toHaveBeenCalled();
     // Polite live region: the connection and who is waiting, nothing that ticks.