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/Services/DashboardSummaryService.cs

@@ -0,0 +1,74 @@
+using Marathon.Application.Abstractions;
+using Marathon.Domain.ValueObjects;
+using Microsoft.Extensions.Options;
+
+namespace Marathon.UI.Services;
+
+/// <summary>
+/// Repository-backed implementation of <see cref="IDashboardSummaryService"/>.
+/// Composes server-side counts (no full-table materialisation) with the top few
+/// anomaly signals and the worker-toggle state. Scoped — captures the per-circuit
+/// repository scope like the other browsing services.
+/// </summary>
+public sealed class DashboardSummaryService : IDashboardSummaryService
+{
+    private const int LatestSignalCount = 5;
+
+    private readonly IEventRepository _events;
+    private readonly ISnapshotRepository _snapshots;
+    private readonly IAnomalyRepository _anomalies;
+    private readonly IAnomalyBrowsingService _anomalyBrowsing;
+    private readonly IOptionsMonitor<WorkerOptions> _workers;
+
+    public DashboardSummaryService(
+        IEventRepository events,
+        ISnapshotRepository snapshots,
+        IAnomalyRepository anomalies,
+        IAnomalyBrowsingService anomalyBrowsing,
+        IOptionsMonitor<WorkerOptions> workers)
+    {
+        _events = events ?? throw new ArgumentNullException(nameof(events));
+        _snapshots = snapshots ?? throw new ArgumentNullException(nameof(snapshots));
+        _anomalies = anomalies ?? throw new ArgumentNullException(nameof(anomalies));
+        _anomalyBrowsing = anomalyBrowsing ?? throw new ArgumentNullException(nameof(anomalyBrowsing));
+        _workers = workers ?? throw new ArgumentNullException(nameof(workers));
+    }
+
+    public async Task<DashboardSummary> GetAsync(CancellationToken ct)
+    {
+        var todayStart = new DateTimeOffset(MoscowTime.Now.Date, MoscowTime.Offset);
+
+        var eventsTracked = await _events.CountAsync(ct).ConfigureAwait(false);
+        var snapshotsToday = await _snapshots.CountSinceAsync(todayStart, ct).ConfigureAwait(false);
+        // DateTimeOffset.MinValue lower bound counts every row (year dominates the
+        // lexical comparison regardless of offset).
+        var anomaliesTotal = await _anomalies.CountSinceAsync(DateTimeOffset.MinValue, ct).ConfigureAwait(false);
+        var anomaliesToday = await _anomalies.CountSinceAsync(todayStart, ct).ConfigureAwait(false);
+        var sports = await _events.ListDistinctSportCodesAsync(ct).ConfigureAwait(false);
+
+        var latest = anomaliesTotal == 0
+            ? (IReadOnlyList<AnomalyListItem>)Array.Empty<AnomalyListItem>()
+            : (await _anomalyBrowsing.ListAsync(new AnomalyFilter(), ct).ConfigureAwait(false))
+                .Take(LatestSignalCount)
+                .ToList();
+
+        var w = _workers.CurrentValue;
+
+        return new DashboardSummary(
+            EventsTracked: eventsTracked,
+            SnapshotsToday: snapshotsToday,
+            AnomaliesTotal: anomaliesTotal,
+            AnomaliesToday: anomaliesToday,
+            SportsCovered: sports.Count,
+            LatestSignals: latest,
+            ScheduleStatus: StageStatus(w.UpcomingPollerEnabled, eventsTracked > 0),
+            SnapshotStatus: StageStatus(w.LivePollerEnabled, snapshotsToday > 0),
+            DetectorStatus: StageStatus(w.AnomalyDetectionEnabled, anomaliesTotal > 0),
+            ExportStatus: eventsTracked > 0 ? "ok" : "idle");
+    }
+
+    // Maps a worker stage to the PipelineStep token: disabled → idle, enabled but
+    // not yet producing → warn (waiting), enabled and producing → ok.
+    private static string StageStatus(bool enabled, bool producing) =>
+        !enabled ? "idle" : producing ? "ok" : "warn";
+}