Summary

• Update version to 0.7.4 and add release notes
• Context overflow auto-compaction (bug: no auto-compaction on context overflow — session fails instead of recovering #314, fix(sessions): auto-compact on context overflow instead of failing the turn #340)
• Skill preservation across compaction and YAML frontmatter stripping (feature: capability grounding — LLM must not claim actions it didn't verifiably execute #324, fix(skills,sessions): strip frontmatter from injected skills, preserve skills across compaction #339)

Changes

• Directory.Build.props — bump VersionPrefix from 0.7.3 to 0.7.4, update PackageReleaseNotes
• RELEASE_NOTES.md — add 0.7.4 entry

Test plan

• dotnet build — 0 warnings, 0 errors
• dotnet test — 1,156 tests passed