Description:
In Multibranch Pipeline projects, branch jobs are automatically managed by Jenkins through the Branch API. Currently, there is no way to selectively disable a branch job in the GUI (or persistently via API). Users can only:

• Remove branches from indexing via filters (wildcards, build strategies).

• Add conditional logic in Jenkinsfile to skip builds.

• Delete branches or rely on SCM clean-up.

This makes it difficult to archive or temporarily disable specific branches while preserving their history.

Proposal:
Introduce the ability to disable/enable individual branch jobs in a Multibranch Pipeline, similar to Freestyle or standalone Pipeline jobs.

Acceptance Criteria:

• A “Disable Project” action is available on each branch job page.

• Disabled branch jobs are marked in the Jenkins UI (e.g., greyed out, labelled “disabled”).

• A disabled branch job will not trigger automatically, nor accept manual builds.

• The disabled state persists across branch indexing/re-scans.

• REST/API endpoints support /disable and /enable for branch jobs.

Advantages:

• ✅ Provides fine-grained control over which branches should build.

• ✅ Preserves build history and logs while stopping future builds.

• ✅ Avoids SCM changes (no need to edit Jenkinsfile to skip).

• ✅ Useful for archiving release or feature branches.

• ✅ Reduces unnecessary CI/CD load for obsolete branches.

Disadvantages / Considerations:

• ⚠️ Conflicts slightly with Branch API philosophy (automatic job management).

• ⚠️ Requires persistence of disabled state across SCM indexing.

• ⚠️ Needs careful handling of Job.Configure permissions to prevent misuse.

• ⚠️ May create user confusion if disabled branches remain visible but unbuildable.

Use Cases:

• A team wants to archive release-1.0 but keep build logs, without deleting it.

• Temporarily disabling noisy branches that are causing build queue congestion.

• Selectively disabling legacy branches while continuing to build active ones.