deslop 0.21.0

What's Changed

• Consolidate cross-crate test scaffolding into a shared deslop-test-support crate by @MelbourneDeveloper in #247
• Fix serde struct-field false positives (#224), CLI schema_doc bloat, and Dart MCP language label (#164) by @MelbourneDeveloper in #248
• Stamp every workspace crate in Cargo.lock (fix v0.21.0 release --locked failure) by @MelbourneDeveloper in #249

Full Changelog: v0.20.0...v0.21.0