improve architecture skill writes mermaid diagrams that fail to parse when an arrow label contains a .

### Skill improve-codebase-architecture ### Harness and version Claude Code 2.1.296, installed as plugin, version 1.3.1 ### Model and effort Opus 5.5, medium efort ### What happened The HTML architecture review produced by the improve architecture skill had a diagram that would not draw. The first diagram in item 1 showed a mermaid syntax error. The other diagrams on the page drew fine. Cause The skill wrote a dotted arrow whose label contains a period: `S -.walks variable.pending.-> FV[(FormalVariable)]` In mermaid, the label on a dotted arrow (-. text .->) ends at the first .. Here it ends after variable, and mermaid can't read the rest of the line: ``` Lexical error on line 2. Unrecognized text. ... S -.walks variable.pending.-> FV[(Form -----------------------^ ``` ### What you expected Have the skill always write arrow labels as -->|"..."| / -.->|"..."|. Code reviews often put dotted names like obj.attr or module.func in labels, so the inline -. text .-> form will keep breaking. Better still, have the skill run its diagrams through mermaid.parse before writing the file.