[josemontespg]

Summary

Add a developer guide for the @a2ui/catalog-iframe and @a2ui/catalog-mcp packages under docs/public/guides/iframe-and-mcp-catalogs.md and link to it from the catalog READMEs and the MkDocs navigation.

The guide covers when to use WebAppFrameSrcdoc, WebAppFrameUrl, and McpApp, installing the packages, serving and configuring the /a2ui-sandbox/ outer proxy asset with Angular CLI, Vite, and static servers, registering the A2UI v1.0 catalogs (@a2ui/web_core/v1_0, @a2ui/catalog-iframe, @a2ui/catalog-mcp/v1_0) with a web renderer, using the Node-safe @a2ui/catalog-mcp/v1_0/functions entry point, and troubleshooting common integration issues.

Changes

• Add docs/public/guides/iframe-and-mcp-catalogs.md covering installation, sandbox asset deployment, catalog registration, example walkthroughs, wire protocols, Node function usage, and troubleshooting.
• Register the guide in mkdocs.yaml under Guides.
• Link to the guide from the Implementations sections of catalogs/iframe/README.md and catalogs/mcp/README.md.

Verification

• ./scripts/fix_format.sh --check passed.
• python3 scripts/fix_licenses.py --check passed.
• Verified all relative Markdown links and anchors across docs/public/guides/iframe-and-mcp-catalogs.md, catalogs/iframe/README.md, catalogs/mcp/README.md, and mkdocs.yaml.

Pre-launch Checklist

• I read the Contributors Guide.
• My code changes have tests (documentation-only change; no code changes to test).

Related to #3157

[gemini-code-assist]

Code Review

This pull request adds a new comprehensive guide for Iframe and MCP catalogs, including updates to the respective README files and the documentation navigation. The review identified a contradiction between the guide's description of sandbox attributes and the actual specifications, as well as a missing action handler in the MessageProcessor example. Both issues require updates to ensure the documentation is accurate and the provided code examples are functional.