dsh-mermaid-comm: Making AI Output Mermaid Diagrams by Default in Development Conversations

`dsh-mermaid-comm` is a DeepSeek Harness plugin designed to guide the AI to prioritize outputting Mermaid diagrams that pass validation. It uses system prompts to guide the AI to draw diagrams in scenarios such as architecture, sequence, and state, registers a `mermaid_validate` tool for secure validation, and leverages an output gate mechanism to repair code or remove failed renderings. The plugin's core is Mermaid Vault, which is responsible for persisting diagrams to a local directory, supporting versioned iterative management, and ensuring diagrams become manageable assets. Installation requires the `dsh-mermaid` plugin and provides security mechanisms such as filename sanitization, directory locking, and atomic writing.