package:pubviz v6.2.0

• Now supports dart run pubviz@.
• Faster local web serving via pre-gzipped embedded assets with HTTP
  Content-Encoding: gzip.
• Added native Mermaid diagram support:
  • Added the print-mermaid action (-a print-mermaid) to print the
    dependency graph as a Mermaid flowchart.
  • Added Mermaid export options ("Copy Mermaid" and "Save Mermaid") to the
    web UI.
• Require sdk: ^3.12.0.