feat: BOC ledger-integration frontend + backend fixes

- Uppdatera robust_client.go med rätt tabellnamn (boc_chart_of_accounts, boc_journal_lines, boc_journal_entries)
- Uppdatera kolumnnamn (entry_id istället för journal_entry_id, account_code istället för code)
- Hantera både stora och små bokstäver för account_type
- Lägg till ledgerApi i frontend med BalanceSheet, IncomeStatement, MomsReport
- Uppdatera DashboardPage med Ledger KPI-kort
- Lägg till LEDGER_DB_URL i docker-compose.yml
- Uppdatera Dockerfile till golang:1.25-alpine

backend/handlers/ledger_v2.go

@@ -0,0 +1,89 @@
+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"boc/ledger"
+)
+
+var ledgerDBURL = getEnv("LEDGER_DB_URL", "postgres://wavult_admin:efG15aKjqgu7uotZoAiLTRBtBDMoXITxIe9Hi6EB@platform-identity-core.cvi0qcksmsfj.eu-north-1.rds.amazonaws.com:5432/amos?sslmode=disable")
+
+// LedgerV2Handler uses direct DB connection for reliable data
+type LedgerV2Handler struct {
+	client *ledger.RobustClient
+}
+
+// NewLedgerV2Handler creates a handler with DB connection
+func NewLedgerV2Handler() (*LedgerV2Handler, error) {
+	client, err := ledger.NewRobustClient(ledgerDBURL)
+	if err != nil {
+		return nil, err
+	}
+	return &LedgerV2Handler{client: client}, nil
+}
+
+// GetAccounts returns all BAS accounts
+func (h *LedgerV2Handler) GetAccounts(w http.ResponseWriter, r *http.Request) {
+	accounts, err := h.client.GetAccounts(r.Context())
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(map[string]interface{}{
+		"accounts": accounts,
+	})
+}
+
+// GetBalanceSheet returns balance sheet for a period
+func (h *LedgerV2Handler) GetBalanceSheet(w http.ResponseWriter, r *http.Request) {
+	period := r.URL.Query().Get("period")
+	if period == "" {
+		period = "2026-01"
+	}
+
+	bs, err := h.client.GetBalanceSheet(r.Context(), period)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(bs)
+}
+
+// GetIncomeStatement returns P&L for a period
+func (h *LedgerV2Handler) GetIncomeStatement(w http.ResponseWriter, r *http.Request) {
+	period := r.URL.Query().Get("period")
+	if period == "" {
+		period = "2026-01"
+	}
+
+	is, err := h.client.GetIncomeStatement(r.Context(), period)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(is)
+}
+
+// GetMomsReport returns VAT report for a period
+func (h *LedgerV2Handler) GetMomsReport(w http.ResponseWriter, r *http.Request) {
+	period := r.URL.Query().Get("period")
+	if period == "" {
+		period = "2026-01"
+	}
+
+	report, err := h.client.GetMomsReport(r.Context(), period)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(report)
+}