feat: add ActivatedDate/ClosedDate to work items and remove analytics…

[viamus]

… tools

• Add ActivatedDate and ClosedDate fields to WorkItemDto and WorkItemSummaryDto
• Include Microsoft.VSTS.Common.ActivatedDate and ClosedDate in DefaultFields and SummaryFields so they are fetched from Azure DevOps
• Map both fields in MapToDto and MapToSummaryDto
• Remove AnalyticsTools (get_flow_metrics, compare_flow_metrics, get_wip_analysis, get_bottlenecks, get_team_workload, get_aging_report) and their supporting models (FlowMetricsDto, WipAnalysisDto) — Claude can now derive these metrics directly from ActivatedDate/ClosedDate on the work item data
• Update README to reflect all changes

Description

Brief description of the changes in this PR.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Refactoring (no functional changes)

Related Issues

Fixes #(issue number)

Changes Made

Testing

• I have tested these changes locally
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

Checklist

• My code follows the project's coding style
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I have updated the documentation accordingly

Screenshots (if applicable)

Additional Notes