Fix 14 dead links across 11 docs pages

[pratikgx]

Summary

Fourteen links return 404. Eight are docs.openwebui.com links that still use pre-restructure slugs (the two TTS integration pages, the environment reference on the Tavily and Linkup pages, plugin events, and the authentication page). The rest are third-party pages that moved: Tavily, Mistral OCR, Onyx connectors, Continue model providers, the OpenAI completions guide (two pages), Vercel AI Gateway authentication, and Ollama's FAQ, which is now faq.mdx. Every replacement verified live.

Related issue or discussion

None.

Checklist

• I have reviewed the relevant documentation and matched the existing style.
• This PR meets Open WebUI's contribution standards: it is accurate, relevant to users, narrowly scoped, maintainable, and not promotional content, advertising, lead generation, SEO placement, or a request to list a product, service, provider, integration, gateway, tool, or company primarily for visibility.
• I understand that PRs that do not meet these standards may be closed without review and will not be merged. Repeated, low-quality, off-topic, promotional, or intentionally misleading submissions may result in the contributor being blocked from future participation in Open WebUI repositories.

Notes for reviewers

Link targets only, no wording changes.