Features
- Add semantic Collection authoring to MCP (#5880)
- Improve MCP validation errors with actionable guidance (#5881)
- Add complete, client-compatible MCP output schemas (#5882)
- Improve MCP authoring, compact output, and agent onboarding (#5883)
Fixes
- Fix MCP mutation persistence and deterministic instance ordering (#5878)
- Preserve selection after instance deletion (#5879)
Other changes
- Cover drag gestures in builder e2e (#5876)
Full Changelog: 0.277.0...0.278.0