Fix 4 dead neptune.ai blog links across course docs

[julamarkova-vibe]

neptune.ai was acquired by OpenAI in December 2025 and the entire blog now redirects to the acquisition announcement, so the neptune.ai/blog links in this repo no longer lead to the referenced articles.

This PR fixes 4 dead links:

• the MLOps Landscape tools overview → Wayback Machine snapshot of the original article (last capture before the redirect)
• the three definitional links (AI/ML experiment, model registry, reproducibility) → live glossary pages on bestaiweb.ai that define the same concepts

Disclosure: I'm one of the authors of bestaiweb.ai. I've only used our pages where they genuinely cover the same ground as the dead article; the remaining fixes point to the Internet Archive (pinned to the last capture before the redirect). Happy to switch any of these to archive.org snapshots instead if you prefer.

[fmind]

Thank you — the diagnosis was correct and the report was genuinely useful.

I verified it independently: every neptune.ai/blog URL now returns 308 Permanent Redirect to openai.com/index/openai-to-acquire-neptune/, so all four articles were unreachable. Fixed in #43.

I went with pinned Internet Archive captures for all four rather than the glossary pages — which is the alternative you offered up front, and I appreciate you disclosing the affiliation without being asked. The reasoning: the surrounding prose in each chapter was written against those specific articles, so the archive preserves the actual reference. Each snapshot was verified through the CDX API as a real text/html 200 capture of 43–62 KB rather than a redirect stub.

Your report also surfaced two larger problems sitting behind it:

1. Neptune wound down its external service after the acquisition, so three chapters were still recommending a tracker readers can no longer sign up for. Those now name Comet and ClearML alongside Weights & Biases, and 5.5 gained a short note on vendor risk — a tool disappearing along with its documentation is exactly the lesson that chapter should be teaching.
2. Nothing here was watching for link rot — a reader found it before any check did. feat(docs): check external links on a schedule, and fix the nine that were dead #44 adds a monthly lychee run, and the first full sweep found nine more dead links, including three of my own MLOps Community articles that moved when that site restructured. The whole set now reports zero errors.

Closing in favour of #43 and #44, but the credit for finding it is yours. Thanks for taking the time.