feat: add FTP and SFTP upload support

internal/domain/config_ftp_test.go

@@ -0,0 +1,50 @@
+package domain
+
+import "testing"
+
+func TestDefaultAppConfigIncludesFTPDefaults(t *testing.T) {
+	cfg := DefaultAppConfig()
+	if cfg.FTP.Protocol != FTPProtocolFTP {
+		t.Fatalf("expected default FTP protocol, got %q", cfg.FTP.Protocol)
+	}
+	if cfg.FTP.Port != 21 {
+		t.Fatalf("expected default FTP port 21, got %d", cfg.FTP.Port)
+	}
+	if cfg.FTP.PathPrefix != "snapgo/" {
+		t.Fatalf("expected default path prefix, got %q", cfg.FTP.PathPrefix)
+	}
+	if cfg.FTP.ConnectTimeoutSecs != 10 {
+		t.Fatalf("expected 10 second timeout, got %d", cfg.FTP.ConnectTimeoutSecs)
+	}
+}
+
+func TestNormalizeUsesSFTPDefaultPort(t *testing.T) {
+	cfg := AppConfig{
+		FTP: FTPConfig{
+			Protocol: FTPProtocolSFTP,
+		},
+	}
+	cfg.Normalize()
+	if cfg.FTP.Port != 22 {
+		t.Fatalf("expected SFTP port 22, got %d", cfg.FTP.Port)
+	}
+	if cfg.FTP.AuthMethod != SSHAuthPassword {
+		t.Fatalf("expected password auth default, got %q", cfg.FTP.AuthMethod)
+	}
+}
+
+func TestIsFTPConfiguredRequiresProtocolHostAndUser(t *testing.T) {
+	cfg := DefaultAppConfig()
+	if cfg.IsFTPConfigured() {
+		t.Fatal("empty FTP destination should not be configured")
+	}
+	cfg.FTP.Host = "files.example.com"
+	cfg.FTP.User = "snapgo"
+	if !cfg.IsFTPConfigured() {
+		t.Fatal("host and user should be enough for a normalized FTP config")
+	}
+	cfg.FTP.Protocol = "invalid"
+	if cfg.IsFTPConfigured() {
+		t.Fatal("invalid protocol should not be configured")
+	}
+}