Refactor frontend components and enhance API integration

- Updated frontend-nuxt.mdc to specify usage of composables for API calls.
- Added new AuthCard and ConfirmModal components for improved UI consistency.
- Introduced UserAvatar component for user profile display, replacing previous Gravatar implementation.
- Implemented useFormSubmit composable for handling form submissions with loading and error states.
- Enhanced vitest.config.ts to include coverage reporting for composables and components.
- Removed deprecated useAdminApi and useAuth composables to streamline API interactions.
- Updated login and setup pages to utilize new components and composables for better user experience.

internal/app/services/export_test.go

@@ -0,0 +1,64 @@
+package services_test
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"testing"
+
+	"github.com/andyleap/hnh-map/internal/app"
+	"github.com/andyleap/hnh-map/internal/app/services"
+	"github.com/andyleap/hnh-map/internal/app/store"
+	"go.etcd.io/bbolt"
+)
+
+func newTestExportService(t *testing.T) (*services.ExportService, *store.Store) {
+	t.Helper()
+	db := newTestDB(t)
+	st := store.New(db)
+	mapSvc := services.NewMapService(services.MapServiceDeps{
+		Store:       st,
+		GridStorage: t.TempDir(),
+		GridUpdates: &app.Topic[app.TileData]{},
+	})
+	return services.NewExportService(st, mapSvc), st
+}
+
+func TestExport_EmptyDB(t *testing.T) {
+	export, _ := newTestExportService(t)
+	var buf bytes.Buffer
+	err := export.Export(context.Background(), &buf)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if buf.Len() == 0 {
+		t.Fatal("expected non-empty zip output")
+	}
+	// ZIP magic number
+	if buf.Len() < 4 || buf.Bytes()[0] != 0x50 || buf.Bytes()[1] != 0x4b {
+		t.Fatal("expected valid zip header")
+	}
+}
+
+func TestExport_WithGrid(t *testing.T) {
+	export, st := newTestExportService(t)
+	ctx := context.Background()
+	gd := app.GridData{ID: "g1", Map: 1, Coord: app.Coord{X: 0, Y: 0}}
+	gdRaw, _ := json.Marshal(gd)
+	mi := app.MapInfo{ID: 1, Name: "test", Hidden: false}
+	miRaw, _ := json.Marshal(mi)
+	st.Update(ctx, func(tx *bbolt.Tx) error {
+		if err := st.PutGrid(tx, "g1", gdRaw); err != nil {
+			return err
+		}
+		return st.PutMap(tx, 1, miRaw)
+	})
+	var buf bytes.Buffer
+	err := export.Export(ctx, &buf)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if buf.Len() < 4 {
+		t.Fatal("expected zip data")
+	}
+}