Refactor read-model event dispatch to reduce Handle method complexity

[Copilot]

ReadModelDomainEventHandler.Handle had grown beyond the configured method length threshold while acting as the top-level dispatcher for read-model updates. This change keeps the dispatch behavior intact but moves the iteration logic out of the public entrypoint so the method stays within the complexity limit.

• Dispatcher extraction

  • Reduced Handle to a small entrypoint that either returns the matched handler task or falls back to Result.Success().
  • Moved the handler lookup loop into a private TryHandleDomainEvent helper using an explicit Try...out pattern.

• Behavior-preserving fallback coverage

  • Added a focused test for an unhandled domain event to lock in the existing contract: no repository calls and a successful result when no handler matches.

• Resulting shape

  • The handler map and per-domain switch expressions remain unchanged.
  • Only the dispatch orchestration was simplified.

public Task<Result> Handle(IDomainEvent domainEvent,
                           CancellationToken cancellationToken) =>
    this.TryHandleDomainEvent(domainEvent, cancellationToken, out Task<Result> handledTask)
        ? handledTask
        : Task.FromResult(Result.Success());

Warning

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  • Triggering command: /usr/bin/dotnet dotnet test /home/REDACTED/work/TransactionProcessor/TransactionProcessor/TransactionProcessor.BusinessLogic.Tests/TransactionProcessor.BusinessLogic.Tests.csproj --filter ReadModelDomainEventHandlerTests --no-restore -nologo (dns block)
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Original prompt

---

This section details on the original issue you should resolve

<issue_title>[Complexity] Method ReadModelDomainEventHandler::Handle has 79 lines of code (limit is 50)</issue_title>
<issue_description>Codacy ID: c29a084936da782fe570473b0b917d08

File: TransactionProcessor.BusinessLogic/EventHandling/ReadModelDomainEventHandler.cs
Line: 20
Rule: Complexity (Warning)
Commit: 5b8f3e64d731c7b181b225e9d4117fda74faa3ac

Message: Method ReadModelDomainEventHandler::Handle has 79 lines of code (limit is 50)

**Code Snippet:**
```csharp
        public async Task<Result> Handle(IDomainEvent domainEvent, 
```

</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes [Complexity] Method ReadModelDomainEventHandler::Handle has 79 lines of code (limit is 50) #1362

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