- Move MCP server implementation and tool schemas from cmd/okf into pkg/okf
- Move hub vault operations and lifecycle management from cmd/okf into pkg/sync
- Implement generic frontmatter --filter AST evaluation in pkg/okf/filter.go
- Implement --stale-within temporal horizon staleness engine in pkg/okf
- Introduce okf.SaveOptions and HubOp structures for clean API ergonomics