feat(node): expose OTLP log and metric APIs

[bbednarski9]

Overview

Expose the core OTLP log and metric contracts through the Node.js binding.

This PR is independently rebased on main after #780. It contains only the Node.js/N-API layer and has no branch dependency on the Python, FFI/Go, or dynamic-plugin/docs follow-up PRs. Review and merge it on its own readiness.

• I confirm this contribution is my own work, or I have the right to submit it under this project's license.
• I searched existing issues and open pull requests, and this does not duplicate existing work.

Details

• Add Node.js log severity and metric measurement types.
• Add optional dataSchema and severity mark arguments and the metric() API.
• Add direct OTLP log and metric subscriber configuration and lifecycle APIs.
• Add version 4 observability plugin configuration helpers.
• Update TypeScript declarations, package guidance, and Node.js parity tests.

Validation:

• cargo check -p nemo-relay-node --all-targets
• Prettier checks passed.
• Focused Node.js binding suite: 123 passed.
• Full Node.js suite on the complete feature tree: 379 passed.

Breaking changes: none.

Where should the reviewer start?

Start with crates/node/src/types/mod.rs for the public types and crates/node/src/api/mod.rs for mark emission and subscriber lifecycle behavior.

Related Issues: (use one of the action keywords Closes / Fixes / Resolves / Relates to)

• Relates to: feat(observability): add core OTLP log and metric pipelines #780

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[github-actions]

Fern docs preview: https://nvidia-preview-pull-request-782.docs.buildwithfern.com/nemo/relay/dev

[github-actions]

License Diff

Compared against origin/main.

Lockfile license changes

Lockfile License Changes

Rust

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• None

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• None

Updated/Changed

• None

Node

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• None

Removed

• None

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• None

Python

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• None

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Status output

[license-diff] selected languages: rust, node, python
[license-diff] generating current inventory
[license-diff] current: generating Rust inventory
[license-diff] current: Rust inventory complete (448 packages)
[license-diff] current: generating Node inventory
[license-diff] current: Node inventory complete (367 packages)
[license-diff] current: generating Python inventory
[license-diff] current: Python inventory complete (105 packages)
[license-diff] current inventory complete
[license-diff] checking out base ref origin/main into a temporary worktree
[license-diff] base: generating Rust inventory
[license-diff] base: Rust inventory complete (448 packages)
[license-diff] base: generating Node inventory
[license-diff] base: Node inventory complete (367 packages)
[license-diff] base: generating Python inventory
[license-diff] base: Python inventory complete (105 packages)
[license-diff] base inventory complete
[license-diff] removing temporary base worktree
[license-diff] comparing inventories
[license-diff] rendering Markdown output
[license-diff] done

[bbednarski9]

Stack handoff from #780: this PR owns the Node pending-mark parity for data_schema and severity. I verified the current branch carries both fields through JsPendingMarkSpec in both conversion directions. Please double-check the accompanying tests preserve both fields through middleware pending-mark emission before merge.

[bbednarski9]

Follow-up for Observability V4: please update Node's typed helper surface with the new logs and metrics sections and make helper-created configs default to version: 4.\n\nToday defaultConfig() still emits v3, while core rejects v3 configs that contain logs or metrics. Please add type and helper regression coverage for creating a V4 logs/metrics config.