Summary

• Refactors LogTemplate.Format into focused helpers to cut the cognitive complexity below the 15 point threshold described in Refactor Method to Reduce Cognitive Complexity #592
• Documents the new workflow with XML doc comments so maintainers can quickly understand the formatting pipeline
• keeps the existing log level short-name mapping and localisation behaviour so downstream components remain untouched

Implementation Details

• Rewrote the formatting loop to iterate characters using a state machine while delegating opening brace detection, closing brace resolution, and character routing to dedicated helpers
• Introduced HandleOpeningBrace, HandleClosingBrace, AppendCharacter, and GetValueForTerm to encapsulate the responsibilities previously mixed inside Format
• Added XML documentation summaries to the refactored methods to align with the guidance in CONTRIBUTING.md regarding maintainable, well-documented code
• Preserved localisation-based error handling by raising the same FlowSynxException when an unknown token is encountered, ensuring compatibility with existing telemetry and alerts

Testing

• dotnet test (blocked: dotnet CLI is not available in the current CLI environment)

Closes #592.