The old v1 binary was built with Go 1.23 and rejected Go 1.25 targets.
Migrated .golangci.yml to v2 format: added version field, moved
linters-settings under linters.settings, removed deprecated linters
(structcheck/deadcode/varcheck), merged gosimple into staticcheck.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>