[mjuraga]

Summary

• Preserve model helper files during clean regeneration and report generated/tidy diffs and untracked files clearly. The helper-preserving cleanup is already present in the base branch.
• Run e2e against the branch's Makefile default (HAProxy 3.4 on master), with Go selected from go.mod.
• Run independent checks without generation/build/tidy prerequisites hiding downstream failures.
• Update checkout/setup-go/YAML actions and the commit checker, use explicit read-only permissions, and remove duplicate Go caches.
• Align the GitLab Go toolchain with go.mod, use the same pinned license checker, pin the integration runner, and derive the formatter version from go.mod.

Job IDs and existing display names are preserved where possible. Release-branch backports and superseded-run cancellation are not included.

Validation

• Full unit and equal-tag test suites passed with Go 1.26.0.
• Clean make models left no generated-code differences or untracked files.
• make e2e-docker passed against HAProxy 3.4.
• Go lint passed with 0 issues using an isolated cache after regeneration completed.
• Module tidiness, pinned license report/check, actionlint, YAML lint, Dockerfile build checks, and GitLab CI syntax validation passed.
• Local assertion checks cover model-helper preservation, independent jobs, e2e defaults, and tool pins.

YAML lint reports existing warnings and the license checker reports its usual assembly-inspection warning; both exit successfully.