Fix Mermaid sequence diagram rendering in documentation

[Copilot]

Fix Mermaid sequence diagram rendering in documentation

This PR addresses the issue where the architecture.md sequence diagram is not being rendered on the docs website (https://microsoft.github.io/wassette/design/architecture.html).

Root Cause: The mdBook configuration lacked the mdbook-mermaid preprocessor, which is required to render Mermaid diagrams.

Changes Made:

• Explore repository and confirm the issue
• Add mdbook-mermaid preprocessor configuration to docs/book.toml
• Update GitHub Actions workflow to install and use mdbook-mermaid
• Test the documentation build locally
• Verify the rendered output shows the diagram correctly
• Update CHANGELOG.md with the fix
• Exclude mermaid files from spell check CI

Technical Details:

1. Added [preprocessor.mermaid] configuration to docs/book.toml
2. Added mermaid.min.js and mermaid-init.js files to docs directory (auto-generated by mdbook-mermaid install)
3. Updated GitHub Actions workflow to download and install mdbook-mermaid v0.14.0
4. Updated .gitignore to exclude mdbook and typos binaries
5. Added mermaid.min.js and mermaid-init.js to typos spell check exclusion list in _typos.toml

Screenshot of Rendered Diagram:

The sequence diagram now renders properly as an interactive Mermaid diagram instead of showing raw code.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>The architecture.md is not rendered as a sequence diagram on the docs website</issue_title>
<issue_description>https://microsoft.github.io/wassette/design/architecture.html still shows unrendered sequence diagram code.</issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes #323

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[Mossaka]

@copilot it looks like the spell check CI failed. Can you ignore the files for mermaid in the spell check CI since we don't own those files?

[Copilot]

@copilot it looks like the spell check CI failed. Can you ignore the files for mermaid in the spell check CI since we don't own those files?

Added mermaid files to the spell check exclusion list in _typos.toml. The files **/mermaid.min.js and **/mermaid-init.js are now excluded from typos spell checking. Commit: 8dc5a2f

[Mossaka]

@copilot display the visual change one more time for me to verify if they are working

[Copilot]

@copilot display the visual change one more time for me to verify if they are working

Here's the rendered Mermaid sequence diagram showing the architecture flow:

The diagram now renders properly as an interactive Mermaid sequence diagram, showing the complete flow:

• Component loading from OCI registries, local files, and HTTP URLs
• WebAssembly compilation and WIT interface extraction
• Component registration with JSON schema generation
• Policy application and WASI state creation
• Tool execution with security policy enforcement