feat(ui): live dashboard, capture-status pill, bet/backtest UX

- Add IDashboardSummaryService/DashboardSummaryService: real event/snapshot/
  anomaly counts, top-5 signals, and per-stage pipeline health from worker state.
- Home: replace hard-coded zeros + placeholder feed with live data, a clickable
  signal feed, and a first-run empty state with a Settings CTA.
- MainLayout: add an appbar capture-status pill (Capturing/Paused) bound to the
  poller toggles, refreshed via IOptionsMonitor.OnChange.
- MyBets: success snackbar on bet submit. Backtest: surface a Cancel button
  while a run is in flight.
- Add en/ru localization for all new strings; register IOptionsMonitor<WorkerOptions>
  in the bUnit test context for layout-rendering tests.

src/Marathon.UI/Pages/MyBets/Journal.razor

@@ -729,6 +729,7 @@
             await Service.AddAsync(_form, ct);
             _form = new AddBetForm();
             _formError = null;
+            Snackbar.Add(L["Journal.Submitted"].Value, Severity.Success);
             await LoadAsync();
         }
         catch (ArgumentException ex)