goimports consistency: hook enforces gofmt only; 2 files carry goimports-style changes #352

From the #341 cold-review thread — follow-up as offered there.

Observation

The pre-commit hook (#343) enforces gofmt -l on staged files, but the repo currently contains goimports-style changes (import reordering/grouping) that gofmt neither produces nor checks. Concretely flagged in the #341 review: lightning.go, offline_wallet_integration_test.go, validator.go (the last fixed in #341's own review round). Meanwhile #341's cleanup PR itself introduced goimports-shaped diffs — meaning the repo's import style is drifting between "whatever the contributor's editor does" and "what gofmt allows".

Options

1. Add a goimports check — extend the pre-commit hook and/or CI with goimports -l (needs goimports installed on contributor machines / a CI step). Strictest: repo becomes goimports-clean going forward.
2. Document gofmt-only as the standard — explicitly state imports are hand-managed; goimports-shaped changes are unwelcome in "gofmt cleanup" PRs but not linted.
3. One-shot normalize + CI pin — a single goimports-everything PR (like chore: gofmt cleanup — 16 files #341 but for imports), then enforce in CI only (not the local hook), avoiding the contributor-tooling requirement.

Option 3 is probably the sweet spot: local hooks stay dependency-free (consistent with #343's portability posture), CI does the enforcing, and the one-shot PR makes the baseline clean.

Happy to take whichever option is preferred — the one-shot normalize is mechanical.