chore: add documentation for OIDC seed setup

[mckornfield]

Summary by CodeRabbit

Documentation

• Enhanced OIDC authentication setup with new seeding section explaining role binding creation
• Clarified how admin email configures platform seeding for PlatformAdmin role assignment
• Added comprehensive auth setup guidance for source installations, including automatic and manual seeding options
• Documented expected outcomes and troubleshooting for missing RBAC bindings

[github-actions]

🌿 Preview your docs: https://nvidia-preview-address-auth-seed-docs-needs-mck.docs.buildwithfern.com/nemo-platform

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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Review profile: CHILL

Plan: Enterprise

Run ID: 9de92141-85ec-4c4b-a88c-e07501554155

📥 Commits

Reviewing files that changed from the base of the PR and between 8111245 and 5967f38.

📒 Files selected for processing (3)

• docs/auth/authentication/oidc.mdx
• docs/auth/deployment/configuration.mdx
• docs/get-started/setup.mdx

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📝 Walkthrough

Walkthrough

Updates docs to state that platform-seed creates initial auth role bindings, adds source-install and manual seeding instructions, documents the missing-seed 403 Forbidden case, and inserts an OIDC setup step for seeding before verification.

Changes

Auth seeding documentation

Layer / File(s)	Summary
Seeded auth bootstrap guidance docs/auth/deployment/configuration.mdx, docs/get-started/setup.mdx	Clarifies that admin_email is applied through platform-seed, documents Helm and source-install seeding paths, includes manual seed commands and readiness checks, and describes the unseeded 403 Forbidden behavior.
OIDC setup step updates docs/auth/authentication/oidc.mdx	Adds a “Seed Auth Role Bindings” step to the OIDC guide, explains the bindings created by seeding, and renumbers the later verify step accordingly.

Suggested labels

docs

Suggested reviewers

• maxdubrinsky

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the main change: adding documentation for OIDC seed setup.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
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.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch address-auth-seed-docs-needs/mck

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[github-actions]

Suite	Lines Covered	Line Rate	Branch Rate
Unit Tests	21176/27762	76.3%	61.2%
Integration Tests	12211/26531	46.0%	19.5%