feat(driver-pwa): pure money/phone/amount helpers + tests

Co-Authored-By: claude-flow <ruv@ruv.net>

driver-pwa/frontend/src/lib/format.test.ts

@@ -0,0 +1,17 @@
+import { describe, it, expect } from "vitest";
+import { formatMoney, formatPhone, digitsOnly } from "./format";
+
+describe("format", () => {
+  it("formatMoney groups thousands and adds ₽", () => {
+    expect(formatMoney(1000)).toBe("1 000 ₽");
+    expect(formatMoney(-3200)).toBe("−3 200 ₽");
+    expect(formatMoney(0)).toBe("0 ₽");
+  });
+  it("digitsOnly strips non-digits", () => {
+    expect(digitsOnly("+7 (914) 305-44-00")).toBe("79143054400");
+  });
+  it("formatPhone renders +7 mask progressively", () => {
+    expect(formatPhone("9143054400")).toBe("+7 914 305-44-00");
+    expect(formatPhone("914305")).toBe("+7 914 305");
+  });
+});