#9336 docs(library): update dify-alternatives

Summary

• Refreshes the library post dify-alternatives (apps/sim/content/library/dify-alternatives/index.mdx).
• Title unchanged.
• A replacement article was merged into the existing post.
• Requested change: MERGE this refresh into the existing library post at library/dify-alternatives and never swap or replace the existing post wholesale. Keep the existing title, every existing FAQ question verbatim unless factually wrong, every H2 and H3, every product compared, every outbound citation, every number o…

Generated by the Library Post PR Updater workflow. Not built or tested locally. After the PR opens, the workflow content gate checks changed paths, frontmatter keys, FAQ placement, and internal links; CI check:library-content validates the post once it is enabled.

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