Remove NRL docs and Perflab baseline reporting

[jioffe502]

Summary

• remove the NRL harness README, guides, design-history page, nightly README, and BO767 walkthrough
• remove the Perflab/release-baseline loader and Slack side-by-side comparison block
• remove the --reference-file and release_references compatibility surfaces entirely
• remove the associated baseline test fixture and nightly configuration example
• keep the harness runner, benchmark runfiles, artifact/history/portal flows, nightly launcher, and ordinary Slack posting intact

Why

Perflab is the canonical home for performance results and comparisons. This removes the ad hoc baseline presentation from NRL while preserving the harness implementation for the separate code decision.

Validation

• git diff --check passes
• focused Slack tests pass: 12 passed
• focused Slack tests pass: 12 passed
• no Perflab, release-reference, or reference-file integration remains in the repository
• replacement benchmarking docs link to the internal NRB repository
• the harness runner and nightly orchestration remain in the tree
• the full nightly launcher test file cannot run on this macOS host because its unchanged Bash 4+ [[ -v "$name" ]] construct is rejected by system Bash 3.2

[greptile-apps]

Greptile Summary

The PR removes the local NRL harness documentation and Perflab release-reference reporting while retaining benchmark execution, nightly orchestration, artifacts, and ordinary Slack reporting.

• Deletes the release-reference loader, CLI option, environment configuration, Slack comparison block, and associated tests.
• Replaces local harness documentation with links to the separate NRB repository.
• Removes obsolete guides, walkthroughs, expected-result documentation, and nightly documentation.

Confidence Score: 3/5

The PR should not merge until the replacement benchmark documentation is reachable by its intended audience and the outstanding public-interface compatibility violation is resolved.

Public documentation now points exclusively to an internal GitLab repository, while the CLI and Python reference-reporting inputs remain removed without the compatibility treatment required by the repository rules.

Files Needing Attention: nemo_retriever/README.md, nemo_retriever/docs/cli/benchmarking.md, nemo_retriever/src/nemo_retriever/harness/cli.py, nemo_retriever/src/nemo_retriever/harness/slack.py

Important Files Changed

Filename	Overview
nemo_retriever/README.md	Replaces deleted local harness guides with an internal GitLab link that is inaccessible to the public README audience.
nemo_retriever/docs/cli/benchmarking.md	Redirects end-to-end benchmarking readers to the same internal-only NRB repository.
nemo_retriever/src/nemo_retriever/harness/cli.py	Removes reference-file loading and the public CLI option; the previously reported rule-governed compatibility break remains outstanding.
nemo_retriever/src/nemo_retriever/harness/slack.py	Removes release-reference rendering and public function parameters while preserving ordinary Slack payload generation.
ops/retriever-nightly/run-nightly.sh	Removes release-reference configuration propagation while retaining nightly execution and ordinary Slack posting.

Prompt To Fix All With AI

### Issue 1
nemo_retriever/README.md:834-835
**Replacement benchmark link is inaccessible**

If a reader lacks access to NVIDIA's internal `gitlab-master.nvidia.com` domain, the sole replacement link for the deleted harness guides cannot be opened, leaving that reader without a usable path to the canonical end-to-end benchmark documentation.

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

_{Reviews (5): Last reviewed commit: "Merge upstream/main into legacy harness ..." | Re-trigger Greptile}

[greptile-apps]

Replacement benchmark link is inaccessible

If a reader lacks access to NVIDIA's internal gitlab-master.nvidia.com domain, the sole replacement link for the deleted harness guides cannot be opened, leaving that reader without a usable path to the canonical end-to-end benchmark documentation.

Rule Used: When this PR changes user-facing code, configurati... (source)

Knowledge Base Used: Benchmark Harness

Prompt To Fix With AI

This is a comment left during a code review.
Path: nemo_retriever/README.md
Line: 834-835

Comment:
**Replacement benchmark link is inaccessible**

If a reader lacks access to NVIDIA's internal `gitlab-master.nvidia.com` domain, the sole replacement link for the deleted harness guides cannot be opened, leaving that reader without a usable path to the canonical end-to-end benchmark documentation.

**Rule Used:** When this PR changes user-facing code, configurati... ([source](.greptile))

**Knowledge Base Used:** [Benchmark Harness](https://app.greptile.com/nvidia-public-github/-/custom-context/knowledge-base/nvidia/nemo-retriever/-/docs/benchmark-harness.md)

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!