Document MSTest 4.3 random test order and MTP 2.3 filter mutual exclusion

[Evangelink]

Summary

Follow-up review of MTP 2.3.0/2.3.1 and MSTest 4.3.0 feature coverage against the docs. The existing documentation (largely from #54187, #54480, and #54633) was already comprehensive; this PR fills the two remaining gaps found during the audit.

Changes

• order-unit-tests.md — Added an "Order randomly" section to the MSTest zone covering the MSTest 4.3 RandomizeTestOrder and RandomTestOrderSeed runsettings options. Previously the article only documented OrderTestsByNameInClass (3.6), so the random-order feature wasn't discoverable from the dedicated ordering article (it was only in the Configure MSTest reference tables).
• microsoft-testing-platform-cli-options.md — Documented the new --treenode-filter ↔ --filter-uid mutual exclusion introduced in MTP 2.3.0 (testfx#9458); added reciprocal notes on both option entries.

Audit result

Every other feature in the MTP 2.3.0/2.3.1 (Changelog-Platform.md) and MSTest 4.3.0 (Changelog.md) changelogs was verified as already documented:

• Analyzers MSTEST0064–0071 (files, overview table, and TOC)
• New assertions (AreSequenceEqual/AreNotSequenceEqual incl. SequenceOrder.InAnyOrder, AreEquivalent, ContainsAll/DoesNotContainAll, AreAllNotNull/AreAllDistinct/AreAllOfType, AddValueFormatter, Span<T>/Memory<T> HasCount overloads, structured messages)
• Condition attributes ([MemberCondition], [ArchitectureCondition], [ExecutableCondition]), class-level [Retry], [AssemblyFixtureProvider], TestContext.Properties lifecycle flow
• Experimental APIs (reflection source generator, ITestFilter/[TestFilterProviderAttribute], TestRun.Current)
• MSBuild parallelization properties and random-order config
• MTP 2.3 CLI/extension surface: --ansi, --progress, crash/hangdump -if-supported options, --list-tests json, --zero-tests-policy, HtmlReport/JUnitReport/CtrfReport/GitHubActionsReport/VideoRecorder/PackagedApp extensions, Azure DevOps publishing/attachments/coverage, Logging bridge, testconfig.json environmentVariables/IConfiguration, two-stage Ctrl+C, LLM-env behavior

MTP 2.3.1 is a single forward-compat bug fix with no user-facing doc need.

ai-usage: ai-assisted

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Internal previews

📄 File	🔗 Preview link
docs/core/testing/microsoft-testing-platform-cli-options.md	Microsoft.Testing.Platform (MTP) CLI options reference
docs/core/testing/order-unit-tests.md	Order unit tests

[Copilot]

Pull request overview

This PR closes two remaining documentation gaps identified in an audit of MSTest 4.3 and Microsoft.Testing.Platform (MTP) 2.3 by updating existing reference articles.

Changes:

• Added an MSTest-focused “Order randomly” section to document RandomizeTestOrder and RandomTestOrderSeed in the dedicated ordering article.
• Documented --treenode-filter ↔ --filter-uid mutual exclusion in the MTP CLI options reference, with notes on both options.

Show a summary per file

File	Description
docs/core/testing/order-unit-tests.md	Adds MSTest 4.3 random ordering guidance to the test ordering article.
docs/core/testing/microsoft-testing-platform-cli-options.md	Adds mutual exclusion notes between --filter-uid and --treenode-filter for MTP 2.3.0+.

Copilot's findings

• Files reviewed: 2/2 changed files
• Comments generated: 4