Also freeze the lnwire and record packages used by the migration.
Copy the minimal subset of lnwire files (16) into
payments/db/migration1/lnwire/ and all record files (6) into
payments/db/migration1/record/. Three lnwire files are trimmed to avoid
pulling in the full message-type dispatch tree — all changes are purely
subtractive and can be verified with:
diff lnwire/message.go payments/db/migration1/lnwire/message.go
diff lnwire/writer.go payments/db/migration1/lnwire/writer.go
diff lnwire/lnwire.go payments/db/migration1/lnwire/lnwire.go
All migration1 files now import only the frozen packages, removing the
live dependency on lnwire and record so future changes to those packages
cannot affect migration correctness.
