Mermaid source and .mmd files

Arialine can create diagrams directly from valid Mermaid source. You can attach a .mmd or .mermaid file, paste Mermaid in an explicitly addressed message, or use the Render as diagram shortcut on an existing message.

Shared .mmd files can also create boards automatically when that channel's automatic Mermaid-file setting is enabled. Pasted Mermaid text is intentionally a separate setting and is off by default to avoid treating code snippets in normal discussion as commands.

If Mermaid is invalid, Arialine either repairs it automatically or offers a manual Let Arialine fix it action depending on the channel's validation setting. Valid Mermaid always renders directly.