Initial commit: haul — desktop SFTP client

A two-pane local/remote file browser over SSH, split out of dial so file
transfer lives in its own tool. The two share ~/.ssh/config as their base.

- internal/sshconf: ~/.ssh/config parsing, for the saved-host list.
- internal/sshx: dialling and auth — agent, keys, password, host-key
  verification, ProxyJump.
- internal/vfs: the FS interface both sides are driven through, implemented
  over the local disk and over SFTP.
- internal/xfer: recursive copy engine with progress reporting, cancellation,
  conflict policy, and resume of partial transfers.
- internal/ui: the Fyne GUI — connect window (saved hosts plus quick connect)
  and the two-pane browser session.

Build with `make build`; the Makefile locates the Go toolchain at ~/.local/go,
which is deliberately kept off PATH. Cross-compiling needs a per-target C
toolchain because Fyne is cgo, so `make dist` builds the native binary only —
the alternatives are documented in the Makefile.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

internal/sshx/live_test.go

@@ -0,0 +1,68 @@
+package sshx
+
+import (
+	"os"
+	"testing"
+
+	"github.com/pkg/sftp"
+)
+
+// TestLiveConnect exercises the real auth + SFTP path against a live host.
+// Gated on DIAL_LIVE_HOST so the normal test suite never needs a server.
+//   DIAL_LIVE_HOST=192.168.192.201 go test ./internal/sshx -run TestLiveConnect -v
+func TestLiveConnect(t *testing.T) {
+	alias := os.Getenv("DIAL_LIVE_HOST")
+	if alias == "" {
+		t.Skip("set DIAL_LIVE_HOST to run the live connection test")
+	}
+	opts := Options{Logf: func(format string, args ...any) { t.Logf(format, args...) }}
+	client, err := Connect(alias, opts)
+	if err != nil {
+		t.Fatalf("Connect(%q): %v", alias, err)
+	}
+	defer client.Close()
+
+	sf, err := sftp.NewClient(client)
+	if err != nil {
+		t.Fatalf("sftp.NewClient: %v", err)
+	}
+	defer sf.Close()
+
+	entries, err := sf.ReadDir(".")
+	if err != nil {
+		t.Fatalf("ReadDir(.): %v", err)
+	}
+	for _, e := range entries {
+		t.Logf("  %s\t%d bytes", e.Name(), e.Size())
+	}
+	t.Logf("SFTP OK: %d entries in remote home", len(entries))
+
+	// Round-trip: write a file, read it back, verify contents, clean up.
+	const remote = "dial-live-test.txt"
+	want := []byte("dial round-trip @ live test\n")
+	w, err := sf.Create(remote)
+	if err != nil {
+		t.Fatalf("Create(%s): %v", remote, err)
+	}
+	if _, err := w.Write(want); err != nil {
+		t.Fatalf("Write: %v", err)
+	}
+	w.Close()
+
+	r, err := sf.Open(remote)
+	if err != nil {
+		t.Fatalf("Open(%s): %v", remote, err)
+	}
+	got := make([]byte, len(want))
+	if _, err := r.Read(got); err != nil {
+		t.Fatalf("Read: %v", err)
+	}
+	r.Close()
+	if string(got) != string(want) {
+		t.Fatalf("round-trip mismatch: got %q want %q", got, want)
+	}
+	if err := sf.Remove(remote); err != nil {
+		t.Fatalf("Remove(%s): %v", remote, err)
+	}
+	t.Logf("round-trip OK: wrote %d bytes, read back identical, removed", len(want))
+}