fix: BOC ledger-integration — fixa robust_client för riktig DB-schema

- Uppdatera GetBalanceSheet att använda entry_date istället för period
- Uppdatera GetIncomeStatement att använda entry_date istället för period
- Uppdatera GetMomsReport att använda entry_date och ta bort status
- Lägg till integrationstester som verifierar mot riktig DB
- Alla tester passerar: GetAccounts, GetBalanceSheet, GetIncomeStatement, GetMomsReport

backend/ledger/integration_test.go

@@ -0,0 +1,69 @@
+package ledger
+
+import (
+	"context"
+	"os"
+	"testing"
+)
+
+// TestIntegration_RobustClient tests against real ledger database
+// Run with: LEDGER_DB_URL=postgres://... go test -run Integration -v ./ledger
+func TestIntegration_RobustClient(t *testing.T) {
+	dbURL := os.Getenv("LEDGER_DB_URL")
+	if dbURL == "" {
+		t.Skip("LEDGER_DB_URL not set, skipping integration test")
+	}
+
+	client, err := NewRobustClient(dbURL)
+	if err != nil {
+		t.Fatalf("Failed to connect to ledger DB: %v", err)
+	}
+	defer client.db.Close()
+
+	ctx := context.Background()
+
+	t.Run("GetAccounts", func(t *testing.T) {
+		accounts, err := client.GetAccounts(ctx)
+		if err != nil {
+			t.Fatalf("GetAccounts failed: %v", err)
+		}
+		t.Logf("Found %d accounts", len(accounts))
+		for _, a := range accounts[:min(5, len(accounts))] {
+			t.Logf("  %s: %s (%.2f)", a.Code, a.Name, a.Balance)
+		}
+	})
+
+	t.Run("GetBalanceSheet", func(t *testing.T) {
+		bs, err := client.GetBalanceSheet(ctx, "2026-01")
+		if err != nil {
+			t.Fatalf("GetBalanceSheet failed: %v", err)
+		}
+		t.Logf("Assets: %.2f, Liabilities: %.2f, Equity: %.2f",
+			bs.TotalAssets, bs.TotalLiabilities, bs.TotalEquity)
+	})
+
+	t.Run("GetIncomeStatement", func(t *testing.T) {
+		is, err := client.GetIncomeStatement(ctx, "2026-01")
+		if err != nil {
+			t.Fatalf("GetIncomeStatement failed: %v", err)
+		}
+		t.Logf("Revenue: %.2f, Expenses: %.2f, Net Income: %.2f",
+			is.TotalRevenue, is.TotalExpense, is.NetIncome)
+	})
+
+	t.Run("GetMomsReport", func(t *testing.T) {
+		moms, err := client.GetMomsReport(ctx, "2026-01")
+		if err != nil {
+			t.Fatalf("GetMomsReport failed: %v", err)
+		}
+		t.Logf("Moms Ut: %.2f, Moms Att Betala: %.2f",
+			moms.MomsUt, moms.MomsAttBetala)
+	})
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}