feat(settings): validate BaseUrl + cron on save, add BaseUrl hint

- Reject a non-absolute / non-http(s) BaseUrl and an implausible (not 5- or
  6-field) cron expression before the section is written to disk, mirroring the
  existing storage-path validation (snackbar + early return).
- Add a hint to the BaseUrl field. Cron check is a lightweight UI guard; the
  worker still does the authoritative Cronos parse at startup.

src/Marathon.Application/UseCases/RunBacktestUseCase.cs

@@ -1,4 +1,5 @@
 using Marathon.Application.Abstractions;
+using Marathon.Application.Storage;
 using Marathon.Domain.AnomalyDetection;
 using Marathon.Domain.Backtesting;
 using Marathon.Domain.Entities;
@@ -46,17 +47,32 @@ public sealed class RunBacktestUseCase
         _logger = logger ?? throw new ArgumentNullException(nameof(logger));
     }
 
-    public async Task<BacktestResult> ExecuteAsync(
+    /// <summary>Runs the backtest over every graded anomaly (no date filter).</summary>
+    public Task<BacktestResult> ExecuteAsync(
         BacktestStrategy strategy,
         CancellationToken ct = default)
+        => ExecuteAsync(strategy, dateRange: null, ct);
+
+    /// <summary>
+    /// Runs the backtest over anomalies detected within <paramref name="dateRange"/>
+    /// (inclusive); pass <c>null</c> to include every graded anomaly. The date filter
+    /// is pushed to SQL via <see cref="IAnomalyRepository.ListByDateRangeAsync"/>.
+    /// </summary>
+    public async Task<BacktestResult> ExecuteAsync(
+        BacktestStrategy strategy,
+        DateRange? dateRange,
+        CancellationToken ct)
     {
         ArgumentNullException.ThrowIfNull(strategy);
 
         _logger.LogInformation(
-            "RunBacktestUseCase: started — bankroll={Bankroll}, minScore={MinScore}, stakeRule={Rule}",
-            strategy.StartingBankroll, strategy.MinScore, strategy.StakeRule);
+            "RunBacktestUseCase: started — bankroll={Bankroll}, minScore={MinScore}, stakeRule={Rule}, range={Range}",
+            strategy.StartingBankroll, strategy.MinScore, strategy.StakeRule,
+            dateRange is null ? "all" : $"{dateRange.From:O}..{dateRange.To:O}");
 
-        var anomalies = await _anomalies.ListAsync(ct).ConfigureAwait(false);
+        var anomalies = dateRange is null
+            ? await _anomalies.ListAsync(ct).ConfigureAwait(false)
+            : await _anomalies.ListByDateRangeAsync(dateRange.From, dateRange.To, ct).ConfigureAwait(false);
         if (anomalies.Count == 0)
         {
             _logger.LogInformation("RunBacktestUseCase: no anomalies — empty result");

src/Marathon.UI/Pages/Anomalies/Backtest.razor

@@ -46,6 +46,25 @@
                                      data-test="backtest-bankroll" />
                 </div>
 
+                <div class="m-backtest__form-field">
+                    <label class="m-backtest__form-label">@L["Backtest.Field.From"]</label>
+                    <MudDatePicker @bind-Date="_form.From"
+                                   DateFormat="yyyy-MM-dd"
+                                   Clearable="true"
+                                   Variant="Variant.Outlined"
+                                   data-test="backtest-from" />
+                </div>
+
+                <div class="m-backtest__form-field">
+                    <label class="m-backtest__form-label">@L["Backtest.Field.To"]</label>
+                    <MudDatePicker @bind-Date="_form.To"
+                                   DateFormat="yyyy-MM-dd"
+                                   Clearable="true"
+                                   Variant="Variant.Outlined"
+                                   data-test="backtest-to" />
+                    <span class="m-backtest__form-hint">@L["Backtest.Field.DateRange.Hint"]</span>
+                </div>
+
                 <div class="m-backtest__form-field">
                     <label class="m-backtest__form-label">@L["Backtest.Field.MinScore"]</label>
                     <MudNumericField T="decimal"

src/Marathon.UI/Pages/Settings.razor

@@ -49,7 +49,7 @@
             <Field Label="@L["Settings.Scraping.RetryBaseDelayMs"]">
                 <MudNumericField T="int" @bind-Value="_scraping.RetryPolicy.BaseDelayMs" Min="100" Max="60000" Variant="Variant.Outlined" />
             </Field>
-            <Field Label="@L["Settings.Scraping.BaseUrl"]">
+            <Field Label="@L["Settings.Scraping.BaseUrl"]" Hint="@L["Settings.Scraping.BaseUrl.Hint"]">
                 <MudTextField T="string" @bind-Value="_scraping.BaseUrl" Variant="Variant.Outlined" />
             </Field>
             <Field Label="@L["Settings.Scraping.RequestTimeoutSeconds"]">
@@ -242,6 +242,20 @@
             }
         }
 
+        if (payload is ScrapingSettingsForm scraping
+            && !(Uri.TryCreate(scraping.BaseUrl, UriKind.Absolute, out var baseUri)
+                 && (baseUri.Scheme == Uri.UriSchemeHttp || baseUri.Scheme == Uri.UriSchemeHttps)))
+        {
+            Snackbar.Add(L["Settings.Scraping.BaseUrl.Invalid"], Severity.Error);
+            return;
+        }
+
+        if (payload is WorkerOptions workers && !IsPlausibleCron(workers.UpcomingScheduleCron))
+        {
+            Snackbar.Add(L["Settings.Workers.Cron.Invalid"], Severity.Error);
+            return;
+        }
+
         var confirmed = await ConfirmAsync();
         if (!confirmed)
         {
@@ -260,6 +274,15 @@
         }
     }
 
+    // Lightweight 5- or 6-field cron sanity check — avoids a Cronos dependency in the
+    // UI layer; the worker still does the authoritative parse at startup.
+    private static bool IsPlausibleCron(string? expression)
+    {
+        if (string.IsNullOrWhiteSpace(expression)) return false;
+        var fields = expression.Split(' ', StringSplitOptions.RemoveEmptyEntries);
+        return fields.Length is 5 or 6;
+    }
+
     private async Task ResetSectionAsync(string section)
     {
         var confirmed = await ConfirmAsync();

src/Marathon.UI/Resources/SharedResource.en.resx

@@ -116,6 +116,9 @@
   <data name="Settings.Scraping.RateLimitRps"><value>Rate limit (RPS)</value></data>
   <data name="Settings.Scraping.RateLimitRps.Hint"><value>Requests per second. 1 is recommended.</value></data>
   <data name="Settings.Scraping.BaseUrl"><value>Base URL</value></data>
+  <data name="Settings.Scraping.BaseUrl.Hint"><value>Must be an absolute http(s) URL, e.g. https://www.marathonbet.by</value></data>
+  <data name="Settings.Scraping.BaseUrl.Invalid"><value>Base URL must be an absolute http(s) address.</value></data>
+  <data name="Settings.Workers.Cron.Invalid"><value>Schedule must be a 5- or 6-field cron expression.</value></data>
   <data name="Settings.Scraping.RequestTimeoutSeconds"><value>Request timeout (sec)</value></data>
   <data name="Settings.Scraping.UsePlaywright"><value>Use Playwright</value></data>
 
@@ -445,6 +448,9 @@
   <data name="Backtest.Section.Equity"><value>Equity curve</value></data>
   <data name="Backtest.Section.Trace"><value>Trade trace</value></data>
   <data name="Backtest.Field.Bankroll"><value>Starting bankroll</value></data>
+  <data name="Backtest.Field.From"><value>From date</value></data>
+  <data name="Backtest.Field.To"><value>To date</value></data>
+  <data name="Backtest.Field.DateRange.Hint"><value>Leave both empty to backtest every graded anomaly.</value></data>
   <data name="Backtest.Field.MinScore"><value>Min anomaly score</value></data>
   <data name="Backtest.Field.MinScore.Hint"><value>Only bet anomalies at or above this confidence.</value></data>
   <data name="Backtest.Field.StakeRule"><value>Staking rule</value></data>

src/Marathon.UI/Resources/SharedResource.ru.resx

@@ -121,6 +121,9 @@
   <data name="Settings.Scraping.RateLimitRps"><value>Лимит RPS</value></data>
   <data name="Settings.Scraping.RateLimitRps.Hint"><value>Запросов в секунду. Рекомендовано 1.</value></data>
   <data name="Settings.Scraping.BaseUrl"><value>Базовый URL</value></data>
+  <data name="Settings.Scraping.BaseUrl.Hint"><value>Должен быть абсолютный http(s)-адрес, например https://www.marathonbet.by</value></data>
+  <data name="Settings.Scraping.BaseUrl.Invalid"><value>Базовый URL должен быть абсолютным http(s)-адресом.</value></data>
+  <data name="Settings.Workers.Cron.Invalid"><value>Расписание должно быть cron-выражением из 5 или 6 полей.</value></data>
   <data name="Settings.Scraping.RequestTimeoutSeconds"><value>Тайм-аут запроса (сек)</value></data>
   <data name="Settings.Scraping.UsePlaywright"><value>Использовать Playwright</value></data>
 
@@ -458,6 +461,9 @@
   <data name="Backtest.Section.Equity"><value>Кривая банка</value></data>
   <data name="Backtest.Section.Trace"><value>Хронология ставок</value></data>
   <data name="Backtest.Field.Bankroll"><value>Стартовый банк</value></data>
+  <data name="Backtest.Field.From"><value>Дата с</value></data>
+  <data name="Backtest.Field.To"><value>Дата по</value></data>
+  <data name="Backtest.Field.DateRange.Hint"><value>Оставьте оба поля пустыми, чтобы прогнать все оценённые аномалии.</value></data>
   <data name="Backtest.Field.MinScore"><value>Мин. score аномалии</value></data>
   <data name="Backtest.Field.MinScore.Hint"><value>Ставим только при уверенности не ниже этого порога.</value></data>
   <data name="Backtest.Field.StakeRule"><value>Правило стейкинга</value></data>

src/Marathon.UI/Services/BacktestService.cs

@@ -23,7 +23,7 @@ public sealed class BacktestService : IBacktestService
         if (!form.IsValid(out var err))
             throw new ArgumentException(err ?? "Invalid form.", nameof(form));
 
-        var result = await _useCase.ExecuteAsync(form.ToStrategy(), ct).ConfigureAwait(false);
+        var result = await _useCase.ExecuteAsync(form.ToStrategy(), form.ToDateRange(), ct).ConfigureAwait(false);
 
         var rows = result.Trace
             .Select(t => new BacktestTraceRow(

src/Marathon.UI/Services/BacktestViewModels.cs

@@ -1,5 +1,7 @@
+using Marathon.Application.Storage;
 using Marathon.Domain.Backtesting;
 using Marathon.Domain.Enums;
+using Marathon.Domain.ValueObjects;
 
 namespace Marathon.UI.Services;
 
@@ -21,10 +23,18 @@ public sealed class BacktestForm
     /// <summary>Bound to the UI as a percentage 0–100; converted to a fraction before sim.</summary>
     public decimal KellyFractionPercent { get; set; } = 25m;
 
+    /// <summary>Optional inclusive date-range filter (Moscow dates). Both null = all anomalies.</summary>
+    public DateTime? From { get; set; }
+
+    /// <summary>Optional inclusive date-range filter (Moscow dates). Both null = all anomalies.</summary>
+    public DateTime? To { get; set; }
+
     public bool IsValid(out string? error)
     {
         if (StartingBankroll <= 0m) { error = "Bankroll must be positive."; return false; }
         if (MinScore is < 0m or > 1m) { error = "Min score must be in [0, 1]."; return false; }
+        if (From is { } f && To is { } t && f.Date > t.Date)
+        { error = "From date must be on or before To date."; return false; }
         switch (StakeRule)
         {
             case StakeRule.Flat:
@@ -52,6 +62,20 @@ public sealed class BacktestForm
             FlatStake: FlatStake,
             PercentOfBankroll: PercentOfBankrollPercent / 100m,
             KellyFraction: KellyFractionPercent / 100m);
+
+    /// <summary>
+    /// The inclusive Moscow-day date range, or null when either bound is unset
+    /// (meaning: run over every graded anomaly).
+    /// </summary>
+    public DateRange? ToDateRange()
+    {
+        if (From is not { } from || To is not { } to)
+            return null;
+
+        return new DateRange(
+            new DateTimeOffset(from.Date, MoscowTime.Offset),
+            MoscowTime.EndOfMoscowDay(DateOnly.FromDateTime(to.Date)));
+    }
 }
 
 /// <summary>UI-facing projection of <see cref="BacktestResult"/>.</summary>

tests/Marathon.Application.Tests/UseCases/RunBacktestUseCaseTests.cs

@@ -1,5 +1,6 @@
 using FluentAssertions;
 using Marathon.Application.Abstractions;
+using Marathon.Application.Storage;
 using Marathon.Application.UseCases;
 using Marathon.Domain.Backtesting;
 using Marathon.Domain.Entities;
@@ -63,6 +64,27 @@ public sealed class RunBacktestUseCaseTests
             StakeRule: StakeRule.Flat,
             FlatStake: 100m, PercentOfBankroll: 0.02m, KellyFraction: 0.25m);
 
+    [Fact]
+    public async Task Should_LoadByDateRange_When_RangeProvided()
+    {
+        var id = new EventId("77777777");
+        var range = new DateRange(BaseTime.AddDays(-1), BaseTime.AddDays(1));
+
+        _anomalies.ListByDateRangeAsync(
+                Arg.Any<DateTimeOffset?>(), Arg.Any<DateTimeOffset?>(), Arg.Any<CancellationToken>())
+            .Returns(new[] { MakeAnomaly(id) }.ToList().AsReadOnly());
+        _events.GetAsync(id, Arg.Any<CancellationToken>()).Returns(MakeEvent(id));
+        _results.GetAsync(id, Arg.Any<CancellationToken>())
+            .Returns(new EventResult(id, 0, 2, Side.Side2, DateTimeOffset.UtcNow));
+
+        var result = await CreateSut().ExecuteAsync(DefaultStrategy(), range, CancellationToken.None);
+
+        await _anomalies.Received(1).ListByDateRangeAsync(
+            Arg.Any<DateTimeOffset?>(), Arg.Any<DateTimeOffset?>(), Arg.Any<CancellationToken>());
+        await _anomalies.DidNotReceive().ListAsync(Arg.Any<CancellationToken>());
+        result.BetsPlaced.Should().BeGreaterThan(0, "the in-range graded anomaly produces a bet");
+    }
+
     [Fact]
     public async Task Should_ReturnEmptyResult_When_NoAnomaliesExist()
     {