feat(my-bets): personal bet journal with CLV tracking

Adds a manual bet-tracking journal that turns the analyzer into an actual
bet tracker. Users record wagers; the journal auto-grades them when event
results land and computes per-bet Closing-Line-Value against the latest
pre-match snapshot — the strongest long-run indicator of betting skill.

Domain:
- PlacedBet entity (reuses Bet vocabulary for Scope/Type/Side/Value/Rate)
  with stake, placed-at, outcome, and notes. Derived GrossReturn / NetProfit.
- BetOutcome enum (Pending / Won / Lost / Void).
- BetOutcomeResolver: pure function grading any Match-scope bet against an
  EventResult. Handles 1X2, draws, handicap (incl. push), and totals.
  Period-scope bets stay manual since EventResult only carries full-time.

Application:
- IPlacedBetRepository abstraction.
- ClosingLineValueCalculator: pure CLV math (implied-probability delta) +
  snapshot-matching predicate by Scope/Type/Side/Value.
- BetJournalReport + BetJournalStats records.
- Four use cases: Record / ResolvePending / BuildReport / Delete.
- New ISnapshotRepository.GetLatestPreMatchAsync pushes the closing-line
  pick into a single SQLite query rather than materialising the 30-day
  window in memory per event.
- ROI turnover excludes Void stakes — pushes are not real turnover and
  including them would dilute the user's edge.

Infrastructure:
- PlacedBetEntity / Configuration / Repository / Mapping helpers.
- 20260516 migration adding the PlacedBets table with EventCode and
  Outcome indices. Intentionally NO foreign key to Events — the journal
  is user data and must survive snapshot-retention pruning. Covered by an
  explicit round-trip test.

UI:
- Pages/MyBets/Journal.razor: hero header, 4-card KPI strip (ROI / strike
  rate / avg CLV / net profit, tinted by tone), inline add-bet form with
  the same invariants as the Bet record, drill-down table with per-row
  outcome pills, CLV percentage-points column, P&L, notes underline, and
  inline-confirm delete. RU + EN i18n.
- Nav entry under Analysis.

Tests: +55 across Domain / Application / Infrastructure (resolver math
including handicap push and total push boundaries, PlacedBet invariants
and derived properties, CLV math + null-handling, four use cases under
NSubstitute, EF round-trip including survives-event-deletion). All 379
tests pass.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/Marathon.Infrastructure/Migrations/MarathonDbContextModelSnapshot.cs

@@ -104,6 +104,26 @@ partial class MarathonDbContextModelSnapshot : ModelSnapshot
             b.ToTable("Sports");
         });
 
+        modelBuilder.Entity("Marathon.Infrastructure.Persistence.Entities.PlacedBetEntity", b =>
+        {
+            b.Property<string>("Id").HasColumnType("TEXT");
+            b.Property<string>("EventCode").IsRequired().HasColumnType("TEXT");
+            b.Property<int>("Scope").HasColumnType("INTEGER");
+            b.Property<int?>("PeriodNumber").HasColumnType("INTEGER");
+            b.Property<int>("Type").HasColumnType("INTEGER");
+            b.Property<int>("Side").HasColumnType("INTEGER");
+            b.Property<decimal?>("Value").HasColumnType("TEXT");
+            b.Property<decimal>("Rate").HasColumnType("TEXT");
+            b.Property<decimal>("Stake").HasColumnType("TEXT");
+            b.Property<string>("PlacedAt").IsRequired().HasColumnType("TEXT");
+            b.Property<int>("Outcome").HasColumnType("INTEGER");
+            b.Property<string>("Notes").HasColumnType("TEXT");
+            b.HasKey("Id");
+            b.HasIndex("EventCode").HasDatabaseName("IX_PlacedBets_EventCode");
+            b.HasIndex("Outcome").HasDatabaseName("IX_PlacedBets_Outcome");
+            b.ToTable("PlacedBets");
+        });
+
         modelBuilder.Entity("Marathon.Infrastructure.Persistence.Entities.AnomalyEntity", b =>
         {
             b.HasOne("Marathon.Infrastructure.Persistence.Entities.EventEntity", "Event")