docs(nav): add Embeddings to the AI Gateway nav in nav.json

[strawgate]

Follow-up to #2063. That PR added the Gateway Embeddings reference page to the mkdocs.yml nav, but docs/nav.json — the separately hand-maintained navigation the embedded docs site renders from — still listed AI Gateway as a single leaf with no Embeddings child, so the page was missing from that navigation.

This mirrors the mkdocs.yml structure in nav.json: AI Gateway becomes a section with Overview + Embeddings.

[coderabbitai]

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📥 Commits

Reviewing files that changed from the base of the PR and between 6e566ea and 709cc04.

📒 Files selected for processing (1)

• docs/nav.json

🔗 Linked repositories identified

CodeRabbit considers these linked repositories for cross-repo context during reviews:

• pydantic/logfire (manual)
• pydantic/pydantic-ai (manual)
• pydantic/pydantic (auto-detected)

🚧 Files skipped from review as they are similar to previous changes (1)

• docs/nav.json

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📝 Walkthrough

Walkthrough

Updated the AI Gateway documentation navigation from a single direct link to a grouped menu. The menu now includes separate Overview and Embeddings links.

Possibly related PRs

• pydantic/logfire#2063: Adds the embeddings reference page and wires it into the gateway documentation.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately summarizes the main change: adding Embeddings to the AI Gateway navigation in nav.json.
Description check	✅ Passed	The description matches the change and explains that nav.json now mirrors mkdocs.yml with Overview and Embeddings.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch claude/gateway-embeddings-nav-json

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