Support creating a mermaid js embedding

[EricTheMagician]

Have you read a contributing guide?

• I have read CONTRIBUTING.md
• I have searched the existing requests and didn't find any that were similar
• I have considered creating a pull request instead and want to proceed

Clear and concise description of the problem

I want to be able to create an embedding directly, specifically the mermaid.js embedding from mermaid markdown.

Suggested solution

When a mermaid markdown block is surrounded by $$ (as this is what is currently returned), we should create the embeding.

Alternative

No response

Additional context

This would be super useful for the mcp server to be able to have an llm generate the mermaid diagram and have it rendered correctly in anytype without any additional steps

[dmitri-b]

+1 still broken on the current API via MCP create-object. Had multiple attempts to find a workaround with opus 4.6 and 4.7 and wasn't successful. The impact is that llms that are outputting pages with mermaid which is not getting rendered by anytype.

opencode analysis:
Root cause in anytype-heart, not the API layer. The body passed to create-object goes through core/block/import/markdown/anymark/blocks_renderer.go, which has no handler for BlockContentLatex. It only emits text / header / list / checkbox / image / divider / table / file blocks. Both $$…$$ and ``mermaid ``` ` fall through:

• $$…$$ → plain text paragraph with literal $$.
• ``mermaid ``` ` → inert code block with language "mermaid".
  Reproduction:
  POST /v1/spaces/{space_id}/objects
  {
  "type_key": "page",
  "name": "mermaid api test",
  "body": "$$\ngraph TD\n A --> B\n$$"
  }
  GET the object → stored as a plain paragraph. Creating the same content manually in desktop (typing $$) produces a proper latex block that renders as Mermaid.
  Same bug, importer side: anytype-heart#1927 (Markdown importer does not handle mermaid/latex blocks anytype-heart#1927) — closed "completed" but never shipped; renderer still has no latex/mermaid handler on develop.
  Fix (either):

1. In the markdown renderer, detect ``mermaid ``` and $$…$$, emit BlockContentLatex with the right Processor. Fixes create-object` and the Obsidian importer in one change.
2. Expose a blocks array on create-object (or an add-block endpoint) so clients can construct a latex block directly.