v0.2.0 - Full v2 Rewrite & Local-First AI Archive

Highlights

• Full v2 rewrite - local-first AI memory archive with MCP server, semantic search, and
  universal sync
• New embeddings - OpenAI backend (text-embedding-3-small/large) + variable context-aware
  chunking
• Search improvements - platform filter, time filters, sort by time
• Summarization - proportional thread summaries with configurable model/API
• License - changed from MIT to AGPL-3.0
• Community - code of conduct, contributing guide, security policy, issue/PR templates
• CI - GitHub Actions workflow