Replace the hand-migrated v2 config with the exact output of
golangci-lint migrate under v2.12.2, applied and verified on
dnswatcher (sha256 8804ff50ebba0e8b4129a03600137040421e43aef9b4054a626abfd13767b28b):
- disable deprecated gomodguard (gomodguard_v2 stays enabled via
default: all; identical behavior, resolves the deprecation warning)
- add linters.exclusions and formatters.exclusions (generated: lax,
default path excludes) replicating v1 defaults
- add explicit formatters block (gofmt, gofumpt, goimports); gci is
intentionally not enabled because its two-group import ordering
conflicts with the org's stdlib/third-party/local script/fmt style
- drop the explanatory header comment so the file is byte-identical
with the verified copy consuming repos fetch
Update the TODO.md Completed Steps entry to match.