[tannevaled]

Summary

Binds the pure-Go SFTP wire codec go-ruby-net-sftp/net-sftp into rbgo as require "net/sftp", so Net::SFTP works with no .rb file.

SFTP runs over an SSH channel. The library owns only the deterministic packet codec (framing, the version-aware ATTRS struct, request-id correlation, version negotiation); the encrypted SSH transport is the host's job — the channel seam. rbgo has no go-ruby-ssh yet, so Net::SFTP.start / Session.new take an injected channel object responding to #write(bytes) / #read(n) (a duck-typed SSH channel, e.g. a StringIO), mirroring how Redis.new takes an injected IO connection. The binding writes FXP_INIT, negotiates the version from FXP_VERSION, then for each operation writes the request frame and reads the id-correlated response.

Ruby surface

• Session: protocol_version/version, open!/close!/read!/write!, stat!/lstat!/fstat!/setstat!/fsetstat!, opendir!/readdir!, remove!/mkdir!/rmdir!/realpath!, rename!/readlink!/symlink!/link!/block!/unblock!, upload!/download!, dir, file.
• Operations::Dir #foreach/#entries; Operations::FileFactory #open/#directory?; Operations::File #read/#write/#pos/#close.
• Value objects: Protocol::V01::Attributes (size/uid/gid/owner/group/permissions/atime/mtime/type + directory?/file?/symlink?) and Name (name/filename/longname/attributes + predicates), with the v4+ longname synthesised on demand.
• Errors: Net::SFTP::Exception < StandardError and Net::SFTP::StatusException carrying code/description/text/message; Net::SFTP::Constants (StatusCodes/PacketTypes).

Wiring

providedFeatures["net/sftp"], vm.registerNetSFTP() after registerNetHTTP (nests under the existing Net module), and classOf cases for the six wrapper types.

Verification

• go build ./... and 6-arch build (amd64/arm64/riscv64/loong64/ppc64le/s390x) — no FAIL.
• 100% coverage of the new files (net_sftp.go, net_sftp_bind.go) via a deterministic in-process channel whose reply frames are built with the same wire codec — no SSH, network, or goroutine.
• Full internal/vm suite green; gofmt -l clean; go vet clean; -race clean.

🤖 Generated with Claude Code

[tannevaled]

Superseded by the net-wave consolidation PR (single merge onto main; shared builtins/require/object_model). Work preserved verbatim; branch kept.