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/sshx_test.go

@@ -0,0 +1,68 @@
+package sshx
+
+import "testing"
+
+func TestParseSSHG(t *testing.T) {
+	// Representative `ssh -G` output (abridged, real keys/casing).
+	out := `host web1
+hostname 10.0.0.5
+user deploy
+port 2222
+proxyjump bastion
+identityfile ~/.ssh/id_ed25519
+identityfile ~/.ssh/id_rsa
+userknownhostsfile ~/.ssh/known_hosts ~/.ssh/known_hosts2
+stricthostkeychecking accept-new
+identityagent SSH_AUTH_SOCK
+`
+	p := parseSSHG("web1", out)
+	if p.HostName != "10.0.0.5" {
+		t.Errorf("hostname = %q", p.HostName)
+	}
+	if p.User != "deploy" || p.Port != "2222" {
+		t.Errorf("user/port = %q/%q", p.User, p.Port)
+	}
+	if p.ProxyJump != "bastion" {
+		t.Errorf("proxyjump = %q", p.ProxyJump)
+	}
+	if len(p.IdentityFiles) != 2 {
+		t.Errorf("identityfiles = %v", p.IdentityFiles)
+	}
+	if len(p.KnownHostsFile) != 2 {
+		t.Errorf("knownhosts = %v", p.KnownHostsFile)
+	}
+	if p.StrictHostKey != "accept-new" {
+		t.Errorf("stricthostkey = %q", p.StrictHostKey)
+	}
+	if p.Addr() != "10.0.0.5:2222" {
+		t.Errorf("addr = %q", p.Addr())
+	}
+}
+
+func TestParseSSHGIdentitiesOnly(t *testing.T) {
+	p := parseSSHG("h", "hostname h\nidentitiesonly yes\nidentityfile ~/.ssh/special\n")
+	if !p.IdentitiesOnly {
+		t.Error("identitiesonly yes should parse true")
+	}
+	q := parseSSHG("h", "hostname h\nidentitiesonly no\n")
+	if q.IdentitiesOnly {
+		t.Error("identitiesonly no should parse false")
+	}
+}
+
+func TestParseSSHGProxyJumpNone(t *testing.T) {
+	p := parseSSHG("h", "hostname h.example.com\nproxyjump none\nport 22\n")
+	if p.ProxyJump != "" {
+		t.Errorf("proxyjump 'none' should be empty, got %q", p.ProxyJump)
+	}
+	if p.Addr() != "h.example.com:22" {
+		t.Errorf("addr = %q", p.Addr())
+	}
+}
+
+func TestParseSSHGFallbackHostname(t *testing.T) {
+	p := parseSSHG("myhost", "user bob\n")
+	if p.HostName != "myhost" {
+		t.Errorf("hostname should fall back to alias, got %q", p.HostName)
+	}
+}