Official Mermaid family registry

The machine-readable registry in diagram-families.csv is pinned to Mermaid revision 04ee3364045d6573f84034d3c9368cc50233a92f (see compatibility/upstreams.lock). It is the progress source of truth for the full official compatibility goal.

This census contains 32 documented Mermaid families. railroad is one family entry because Mermaid documents four railroad dialects under one syntax family. zenuml is included because it is an official Mermaid syntax entry, although Mermaid loads it as an external diagram package.

The status contract is deliberately strict:

• implemented requires parser, typed AST, layout, SVG renderer, positive and negative fixtures, and platform/test coverage for the declared family scope.
• in_progress means work exists or the family is actively tracked, but the complete contract is not closed.
• not_started means no implementation work has been accepted.
• blocked is reserved for a concrete external or technical blocker.

The current flowchart, sequence, stateDiagram, pie, class, entityRelationshipDiagram, xyChart, and mindmap vertical slices therefore remain in_progress: they are executable and tested, but they are not full family parity. The registry must be updated in the same PR that closes a family's parser, layout, render, and tests; registering a name alone never means support.