Initiële commit: VibeFinance 3-container opzet

Basislijn van de bestaande applicatie (Vite/React frontend, Express
backend, PostgreSQL) zoals die in de index stond, plus dev-, release-
en documentatiescripts.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

frontend/src/utils/format.js

@@ -0,0 +1,33 @@
+/** Euro formatter (nl-NL, geen decimalen) */
+export const fmt = (n) =>
+  new Intl.NumberFormat("nl-NL", {
+    style: "currency", currency: "EUR", maximumFractionDigits: 0,
+  }).format(n || 0);
+
+/** Percentage formatter */
+export const pct = (n, d = 1) => `${((n || 0) * 100).toFixed(d)}%`;
+
+/** ISO datum (YYYY-MM-DD) → Nederlandse notatie (DD-MM-YYYY) */
+export const fmtDatum = (s) => {
+  if (!s) return s;
+  const [y, m, d] = s.split("-");
+  return `${d}-${m}-${y}`;
+};
+
+/** Crypto-bedrag formatter (4 decimalen standaard) */
+export const fmtCrypto = (n, d = 4) => (parseFloat(n) || 0).toFixed(d);
+
+/**
+ * Bedrag in USD of EUR opmaken afhankelijk van geselecteerde valuta.
+ * @param {number} amount
+ * @param {"USD"|"EUR"} currency
+ * @param {number} usdEurRate
+ */
+export function fmtMoney(amount, currency = "EUR", usdEurRate = 0.92) {
+  const v = currency === "EUR" ? amount * usdEurRate : amount;
+  return new Intl.NumberFormat("nl-NL", {
+    style: "currency",
+    currency,
+    maximumFractionDigits: 0,
+  }).format(v || 0);
+}