Clarify module-local setup and teardown discovery

[MariusStorhaug]

Context and request

Process-PSModule documentation should state that module-local workflow setup and teardown are enabled only by the exact repository-root files tests/BeforeAll.ps1 and tests/AfterAll.ps1. The current pipeline-stages page describes discovery in "test directories," which can imply that nested files create workflow phases.

Acceptance criteria

• src/docs/Frameworks/Process-PSModule/pipeline-stages.md identifies tests/BeforeAll.ps1 and tests/AfterAll.ps1 as exact, non-recursive workflow phase files.
• The page states that each phase runs once around the module-local test matrix.
• The page distinguishes these workflow phases from ordinary Advanced test entries, which may be discovered recursively under tests/.
• The documentation build, lint, link, and diff checks pass.

Constraints and non-goals

• Do not change Process-PSModule behavior.
• Do not change PSModule/docs or broaden test-layout profile guidance.
• Keep the correction focused on the canonical MSXOrg/docs pipeline-stage description.

Technical decisions

• Align the wording with PSModule/Process-PSModule main .github/actions/Get-PSModuleSettings/src/main.ps1, which performs exact Test-Path checks for the two root files.
• Preserve recursive discovery language only for ordinary Advanced test entries and explicitly separate that mechanism from workflow phase detection.
• Use PSModule/docs#88 as relevant specialized-standard context.

Implementation plan

• Record the current misleading phrases and the exact live implementation checks as the before-change verification.
• Update only src/docs/Frameworks/Process-PSModule/pipeline-stages.md to define root-only phase discovery and separate it from recursive Advanced test discovery.
• Run the repository documentation link, build, lint, and diff checks.
• Open a draft PR, complete the Copilot review loop, and report the final status.