feat(governance): add independent CR label for ABI changes (#677)

[Ulrond]

What

Adds CR (Change Request) as an independent process/governance label.

CR marks an ABI change that needs:

1. Wider review sign-off on approval — beyond the default CODEOWNERS team, the relevant team:* architecture reviewers must sign off.
2. Separate release scheduling — not folded into the normal cohort sweep; scheduled deliberately.

Why independent (not a rename of Breaking Change)

The change-class labels (Breaking Change / Major Change / Minor Change) answer "how does the version number move?" and are matched by name in scripts/release.sh to compute the bump. CR answers a different question — "is this an ABI change needing wider review + scheduling?" — so it is orthogonal and co-exists with a change-class label (an ABI change is a Breaking Change).

Renaming Breaking Change → CR would conflate the two axes and break the generation-bump detection in release.sh:1304. So the axes stay separate; release.sh never reads CR.

Changes

• scripts/setup_labels.sh — declare CR under a new process/governance section (color 5319e7).
• docs/governance/versioning-sop.md — document CR as an independent, non-bump label + add it to the label reference table.

The live CR label is already created on the repo; this PR makes setup_labels.sh (the declarative source of truth) and the sop agree.

Closes #677

[Copilot]

Pull request overview

Adds an independent governance/process label CR (“Change Request”) to mark ABI changes that require wider review sign-off and deliberate release scheduling, without affecting the version-bump logic driven by change-class labels.

Changes:

• Add CR label definition to scripts/setup_labels.sh under a new “Process / governance labels” section.
• Document the CR label semantics and requirements in docs/governance/versioning-sop.md, and add it to the label reference table.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
scripts/setup_labels.sh	Declares the new CR governance label (name, colour, description) alongside existing label setup.
docs/governance/versioning-sop.md	Documents CR as an independent (non-bump) label and adds it to the label reference table.

Comments suppressed due to low confidence (1)

docs/governance/versioning-sop.md:636

• The “GitHub Labels” reference table is now inconsistent with the earlier change-class documentation and with scripts/setup_labels.sh: it omits the documentation label and describes Minor Change as “Doc-only…”, but documentation is the doc-only label and Minor Change is intended for small non-doc patch-level changes. The paragraph immediately below also says every PR carries exactly one of Breaking/Major/Minor, which excludes documentation.

| Label | Purpose |
|-------|---------|
| `component:<name>` | Maps PRs to a specific HAL/VSI component (auto-detected from metadata.yaml) |
| `Breaking Change` | Breaking interface change — bumps generation |
| `Major Change` | Additive interface change — bumps minor (the default for real work) |
| `Minor Change` | Doc-only / metadata-only / comment-only change — bumps patch |
| `CR` | Change Request — ABI change needing wider review sign-off + separate release scheduling (independent of change-class; no bump effect) |
| `scope:infrastructure` | Repo tooling, CI/CD, governance |
| `scope:overview` | Tracking ticket spanning multiple components |

Every PR carries **exactly one** of `Breaking Change` / `Major Change` /
`Minor Change`. The label signals the bump intent; the PR author bumps