Release 2.2.0: update release notes and version metadata

[Aaronontheweb]

Summary

• Updates RELEASE_NOTES.md with the 2.2.0 release entry (dated July 3rd 2026)
• Updates Directory.Build.props version to 2.2.0 and injects release notes via build script

Changes in this release

Features

• Support get_workspace by slug - The GetWorkspace MCP tool now accepts workspace slugs in addition to IDs; slug matching is case-insensitive

Bug Fixes

• Make MCP tools resilient to missing required parameters - MCP tools now return descriptive error messages when required parameters are missing or malformed; affected tools: Store, Edit, CreateReference, MoveMemory

Test plan

• Verify RELEASE_NOTES.md has correct version header #### 2.2.0 July 3rd 2026 ####
• Verify Directory.Build.props VersionPrefix is 2.2.0
• Verify PackageReleaseNotes in Directory.Build.props matches the 2.2.0 release notes block
• CI checks pass