Document the Ranked attribute type

[davidkrauser]

Add a Ranked entry to the user-attribute type list, document its ordered comparison operators in the system-wide access policy match options, and note that classification markings use the same Ranked attribute type.

[coderabbitai]

📝 Walkthrough

Walkthrough

This PR updates Mattermost documentation to describe a new Ranked user attribute type. Changes clarify that classification markings use Ranked attributes for ordering, and document supported ordered comparison operators for Ranked attributes in ABAC Simple Mode policy configuration.

Changes

Ranked Attribute Documentation

Layer / File(s)	Summary
Ranked attribute type definition source/administration-guide/manage/admin/user-attributes.rst	Adds the Ranked attribute type to the supported types list, describing ordered-value behaviour and threshold-based comparisons.
ABAC Simple Mode comparison options source/administration-guide/manage/admin/abac-system-wide-policies.rst	Documents ordered comparison match options for Ranked attributes (exact/not, at least/greater than, at most/less than) in Simple Mode policy configuration.
Classification markings ordering source/administration-guide/configure/site-configuration-settings.rst	Clarifies that classification level ordering uses the Ranked attribute type, aligning with user attribute behaviour.

Estimated code review effort: 1 (Trivial) | ~3 minutes

Related Issues: None specified

Related PRs: None specified

Suggested labels: documentation

Suggested reviewers: None specified

Poem
A rabbit hops through docs anew,
Ranking levels, low to high, in view.
Thresholds set where matches lie,
Classification ranks reach for the sky.
Three files touched, one concept true. 🐇

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
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.
Title check	✅ Passed	The title clearly summarizes the main documentation change: introducing the Ranked attribute type.
Description check	✅ Passed	The description matches the documented changes to user attributes, policy match options, and classification markings.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch dk-ranked-attribute-docs

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[github-actions]

Newest code from mattermost has been published to preview environment for Git SHA aa30aba

[davidkrauser]

@amyblais quick question about the workflow for documentation changes: if this goes directly into the v11.9 branch, how will it get into master for future releases? Do I need to open another PR for that?

[amyblais]

quick question about the workflow for documentation changes: if this goes directly into the v11.9 branch, how will it get into master for future releases? Do I need to open another PR for that?

@davidkrauser I will merge the v11.9 branch into the master branch via this PR #9043 on the release day.

[esethna]

@pvev friendly ping on review here, thanks!