Fast Mermaid Validator MCP

# Test Invalid Mermaid Syntax This file contains definitely invalid Mermaid syntax that should fail parsing. ## Invalid Flowchart ```mermaid flowchart TD A --> --> B C ~~> D invalid syntax here E -> F{ ``` ## Invalid Sequence Diagram ```mermaid sequenceDiagram participant A participant A->->->B: invalid arrows B<<--A: wrong direction random text ```