Add NATS account-balance SoT and statement review for customers, CS, and sales

Internal billing now uses verae.billing.* request-reply and pubs. zappier-account-balance tracks prepaid, credits, usage, and payments. Portal, admin, CS, and sales all review the same statement. Independent Forgejo repos stay split via push-module-repos.

packages/zappier-account-balance/package.json

@@ -0,0 +1,14 @@
+{
+  "name": "zappier-account-balance",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "description": "NATS source of truth for customer prepaid balances, credits, usage, payments",
+  "scripts": {
+    "start": "node src/server.js",
+    "test": "node --test test/*.test.js"
+  },
+  "dependencies": {
+    "nats": "^2.28.2"
+  }
+}