refactor: move V1 code into v1/ subdirectory

- git mv cmd/ internal/ pkg/ test/ go.mod go.sum Makefile build.sh docs/ v1/
- Create v1/README.md with V1 documentation
- Update root README for V1 + V2 structure
- V1 still builds (cd v1 && go build ./cmd/hostkeeper) and 105 tests pass
- Root is now clean for V2 development

v1/test/storage/export_import_test.go

@@ -0,0 +1,83 @@
+package storage_test
+
+import (
+	"context"
+	"encoding/json"
+	"testing"
+	"time"
+
+	"git.tukangketik.id/swanadiva/hostkeeper/internal/models"
+	"git.tukangketik.id/swanadiva/hostkeeper/pkg/storage"
+)
+
+func TestExportImport(t *testing.T) {
+	tempDir := t.TempDir()
+
+	store, err := storage.NewJSONStorage(tempDir)
+	if err != nil {
+		t.Fatalf("Failed to create storage: %v", err)
+	}
+
+	ctx := context.Background()
+
+	testHost := &models.Host{
+		ID:        "test-host-1",
+		Name:      "Test Server",
+		Hostname:  "192.168.1.100",
+		Port:      22,
+		Username:  "admin",
+		Auth:      models.AuthConfig{Type: "password"},
+		CreatedAt: time.Now(),
+	}
+
+	if err := store.SaveHost(ctx, testHost); err != nil {
+		t.Fatalf("Failed to save host: %v", err)
+	}
+
+	exportedData, err := store.ExportData(ctx)
+	if err != nil {
+		t.Fatalf("Failed to export data: %v", err)
+	}
+
+	if exportedData == nil {
+		t.Fatal("Exported data is nil")
+	}
+
+	if len(exportedData.Hosts) != 1 {
+		t.Fatalf("Expected 1 host, got %d", len(exportedData.Hosts))
+	}
+
+	// Simulate writing to file and reading back
+	jsonBytes, err := json.Marshal(exportedData)
+	if err != nil {
+		t.Fatalf("Failed to marshal export data: %v", err)
+	}
+
+	var importedData storage.ExportData
+	if err := json.Unmarshal(jsonBytes, &importedData); err != nil {
+		t.Fatalf("Failed to unmarshal export data: %v", err)
+	}
+
+	importDir := t.TempDir()
+	importStore, err := storage.NewJSONStorage(importDir)
+	if err != nil {
+		t.Fatalf("Failed to create import storage: %v", err)
+	}
+
+	if err := importStore.ImportData(ctx, &importedData, storage.MergeStrategyReplace); err != nil {
+		t.Fatalf("Failed to import data: %v", err)
+	}
+
+	importedHosts, err := importStore.ListHosts(ctx)
+	if err != nil {
+		t.Fatalf("Failed to list imported hosts: %v", err)
+	}
+
+	if len(importedHosts) != 1 {
+		t.Errorf("Expected 1 imported host, got %d", len(importedHosts))
+	}
+
+	if importedHosts[0].Name != testHost.Name {
+		t.Errorf("Expected host name '%s', got '%s'", testHost.Name, importedHosts[0].Name)
+	}
+}