docs(rl): repoint the refit example links at the split ModelExpress dirs

[ayaangazali]

Summary

lychee is failing on every new PR in this repo, and this is the one broken link causing it:

[404] https://github.com/ai-dynamo/modelexpress/tree/main/examples/rl/dynamo_vllm_refit
      | Rejected status code: 404 Not Found

ai-dynamo/modelexpress split that directory in two. examples/rl still exists and now holds dynamo_vllm_reshard_refit and dynamo_vllm_s3_delta_refit, so the old path is gone.

Worth stating plainly because it looks intermittent: the check still reads SUCCESS on older open PRs such as #13888 and #14021 purely because those runs predate the rename. Any lychee run from now on fails, so this reddens new PRs regardless of what they change. I hit it on #14770, whose diff is two Rust files with no URLs.

The split also dated the sentence the link sits in. It claimed the example "does not qualify the S3 delta path", and there is now a dedicated example for that path: its README publishes a full snapshot v1 plus incremental snapshots d2 and d3 over S3. Repointing the link on its own would have left a sentence that the adjacent link disproves, so each example is now named for what it covers, and the caveat that neither qualifies every backend and topology is kept.

Validation

Both replacement paths were confirmed to exist before linking them, rather than inferred from the naming:

examples/rl/dynamo_vllm_reshard_refit   -> 6 entries
examples/rl/dynamo_vllm_s3_delta_refit  -> 8 entries
examples/rl/dynamo_vllm_refit           -> 404

The description of each example is taken from its own README, not guessed: the reshard one "validates the complete inference-side lifecycle" for a full-weight version over NIXL, and the S3 delta one "exercises the CoreWeave-shaped weight-synchronization lifecycle" with a full snapshot followed by incremental deltas.

No occurrence of dynamo_vllm_refit remains in the file. pre-commit over the changed file passes every hook except pytest-marker-report, which fails identically on a clean tree in this environment because vLLM is not installed.

Docs-only change; no code paths touched.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Documentation
  • Added links to separate vLLM resharding and S3 delta-refit examples.
  • Documented support for artifact refits using a full snapshot plus incremental deltas.
  • Clarified that the examples do not cover every backend or topology.

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[github-actions]

🌿 Fern Docs Preview: https://nvidia-preview-01a09d53-2de1-75cb-8440-3144a7b26c53.docs.buildwithfern.com/dynamo/dev

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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📥 Commits

Reviewing files that changed from the base of the PR and between 13a8523 and 3cdaae8.

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• docs/fern/pages/use-cases/reinforcement-learning/weight-updates.md

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Walkthrough

The ModelExpress refit documentation now separates full-weight trainer-to-inference resharding from S3 artifact delta refitting. It also states the qualification limits for both examples and keeps startup loading as a separate workflow.

Changes

ModelExpress refit documentation

Layer / File(s)	Summary
Refit example links and scope docs/fern/pages/use-cases/reinforcement-learning/weight-updates.md	The page links to separate vLLM reshard and S3 delta refit examples. It documents full-snapshot-plus-incremental-delta coverage and qualification limits for both examples.

Priority: ⬇️ Low

Estimated code review effort: 1 (Trivial) | ~2 minutes

Merge Risk: ⚪ Minimal · up to 3cdaa

The updated documentation links to the split workflows without introducing product or operational risk.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Description check	⚠️ Warning	The description explains the broken link, the replacement paths, the documentation updates, and validation results. However, it does not follow the required template because it omits the "Where should…	Add the required "Where should the reviewer start?" section with the changed file, and add the "Related Issues" section with either the relevant issue reference or the checked confirmation that this PR has no related issue.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main documentation change: it repoints the broken refit example links to the split ModelExpress directories.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0…
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.

Full details: Description check

Explanation

The description explains the broken link, the replacement paths, the documentation updates, and validation results. However, it does not follow the required template because it omits the "Where should the reviewer start?" section and the required "Related Issues" section with an issue link or confirmation that no related issue exists.

• Fix all pre-merge checks with AI

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[athreesh]

/ok to test 3cdaae8

[nv-rinig]

/ok to test 39e410d