docs: fix incorrectly formatted environment variables

[npepinpe]

Description

This PR fixes incorrectly formatted environment variables. I did not go through all the docs, just the security relevant ones.

It also raises the question as to why some are env vars, and others just properties 🤷

Related to https://camunda.slack.com/archives/C0ABV95Q1J8

When should this change go live?

• This is a bug fix, security concern, or something that needs urgent release support. (add bug or support label)
• This is already available but undocumented and should be released within a week. (add available & undocumented label)
• This is on a specific schedule and the assignee will coordinate a release with the Documentation team. (create draft PR and/or add hold label)
• This is part of a scheduled alpha or minor. (add alpha or minor label)
• There is no urgency with this change (add low prio label)

PR Checklist

• The commit history of this PR is cleaned up, using {type}(scope): {description} commit message(s)

• My changes are for an upcoming minor release and are in the /docs directory (version 8.9).
• My changes are for an already released minor and are in a /versioned_docs directory.

• I added a DRI, team, or delegate as a reviewer for technical accuracy and grammar/style:
  • Engineering team review
  • Technical writer review via @camunda/tech-writers unless working with an embedded writer.

[Copilot]

Pull request overview

This PR updates security-related documentation to align environment variable names with the intended configuration property naming scheme across both current (8.9) and versioned (8.8) docs.

Changes:

• Normalize OIDC authentication and assertion-related environment variable names by removing internal underscores to match the relaxed Spring Boot binding pattern.
• Update HTTP header security configuration environment variable names to a consistent flattened style (e.g., HTTPHEADERS_* and CLOCKSKEW/IDTOKENALGORITHM).
• Adjust Identity initialization (authorizations/roles/mapping rules/users) environment variable names to a consistent flattened style in both 8.8 and 8.9 documentation.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
versioned_docs/version-8.8/self-managed/components/orchestration-cluster/core-settings/configuration/properties.md	Aligns 8.8 env-var documentation for OIDC auth, HTTP security headers, and security initialization with the new flattened naming scheme.
docs/self-managed/components/orchestration-cluster/core-settings/configuration/properties.md	Mirrors the same env-var renaming for the 8.9 docs, keeping property/env/Helm documentation in sync for current version.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[npepinpe]

For the tech writers: no clue why it says bad links, I didn't change any link 🤷

[giorgionaps]

Committed minor changes directly to the branch. Otherwise, LGTM!

[github-actions]

👋 🤖 🤔 Hello, @npepinpe! Did you make your changes in all the right places?

These files were changed only in docs/. You might want to duplicate these changes in versioned_docs/version-8.8/.

• docs/self-managed/components/orchestration-cluster/core-settings/configuration/partials/_security.md

These files were changed only in versioned_docs/version-8.8/. You might want to duplicate these changes in docs/.

• versioned_docs/version-8.8/self-managed/components/orchestration-cluster/core-settings/configuration/properties.md

You may have done this intentionally, but we wanted to point it out in case you didn't. You can read more about the versioning within our docs in our documentation guidelines.

[npepinpe]

@giorgionaps - I had to rebase, and there were major changes where the properties.md file was broken up, so I dropped some of your changes. I tried my best to add them back, but could use a quick pass again to make sure it looks good :)

[mesellings]

@npepinpe @giorgionaps approving to merge as I am refactoring this page currently with all the new 8.9 properties, so this looks good to go for me now 👍