v0.5.1

What's Changed

• fix(engine): 防止同步复活旧 backfill notes by @catoncat in #202
• fix(engine): 允许无本地草稿收口 proposal by @catoncat in #201
• Fix oversized Mainline hook context injection by @jiangge in #203
• docs(release): 记录 v0.5.1 发布说明 by @catoncat in #204

Full Changelog: v0.5.0...v0.5.1