refactor: centralize test utilities and improve code organization

Introduce internal/testutil package to share git repository setup helpers across tests, removing duplication. Move shellEscape to utils.go and rename commands_utils_test.go to utils_test.go for better organization.

refactor: reduce cyclomatic complexity in commands.go

docs: update worker instructions to align with engage submit workflow

refactor: reduce cyclomatic complexity in tests

refactor: reduce complexity in commands and improve test coverage

fix: Fix Version Reporting (000006)

commit b1d1976
Author: Tibor Schmidt <[email protected]>
Date:   Sun Jan 25 12:10:53 2026 +0100

    fix: use debug.ReadBuildInfo for version fallback

feat: Enforce ID in Branch Names (000005)

commit 4d6b03a
Author: Tibor Schmidt <[email protected]>
Date:   Sun Jan 25 11:56:35 2026 +0100

    feat: enforce ID in branch names

refactor: reduce cyclomatic complexity and fix ineffectual assignments

feat: implement git-based versioning