Align golangci-lint versions (local vs CI)

[SRodi]

Problem

Local runs use a different golangci-lint version than CI. CI uses golangci-lint-action with version: latest, which can drift and produce warnings that do not reproduce locally.

Goal

Make local and CI use the same golangci-lint version and keep it pinned.

Scope

• CI workflow(s) that run golangci-lint.
• Local tooling path (Makefile and/or documented developer workflow).

Proposed Work

• Identify the current CI golangci-lint version that is being pulled by version: latest.
• Decide on a pinned version to use (prefer the version in go.mod, or update go.mod to match a newer version).
• Update CI workflow to pin the version (e.g., version: vX.Y.Z).
• Update local tooling to use the same version (Makefile and any scripts).
• Document the pinned version and the command to run locally in README or CONTRIBUTING.

Acceptance Criteria

• CI uses a pinned golangci-lint version.
• Local make lint (or equivalent) uses the same version.
• A contributor can reproduce CI lint results locally without version drift.

Notes

• CI workflow: .github/workflows/golangci-lint.yaml
• Local tooling: Makefile and go.mod