[feature] Split synchronization view into subviews

[paul-fresquet]

Summary

• modularize synchronization view into before-start, main status, and statistics subviews
• add corresponding view models and wire them into main view model
• introduce unit tests for new synchronization view models

Testing

• dotnet build --verbosity quiet /property:WarningLevel=0
• dotnet test (fails: The configuration file 'server-common-tests.local.settings.json' was not found and is not optional)

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https://chatgpt.com/codex/tasks/task_e_68a97fc9f4d88333bf4930280175787c

[sonarqubecloud]

Quality Gate passed

Issues
17 New issues
0 Accepted issues

Measures
0 Security Hotspots
81.7% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[Copilot]

Pull Request Overview

This PR modularizes the synchronization view by splitting the monolithic SynchronizationMainViewModel into three specialized subcomponents: before-start, main status, and statistics. This refactoring improves separation of concerns and testability while maintaining the same functionality.

• Extracted synchronization logic into three focused view models with corresponding views
• Introduced comprehensive unit tests for the new view models
• Updated test infrastructure to force English culture for consistent test execution

Reviewed Changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
SynchronizationMainViewModel.cs	Refactored to compose three specialized subview models instead of handling all logic directly
SynchronizationBeforeStartViewModel.cs	New view model handling pre-synchronization start logic and UI state
SynchronizationMainStatusViewModel.cs	New view model managing synchronization status display and abort functionality
SynchronizationStatisticsViewModel.cs	New view model tracking synchronization progress statistics and timing
View files	New AXAML views and code-behind for the three subcomponents
Test files	Comprehensive unit tests covering the new view models with proper mocking and assertions
AbstractTester.cs	Added culture forcing to ensure consistent test execution across environments
AGENTS.md	Updated testing guidelines and coverage requirements

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