Bind each customer to a Verae userId for hop tracing

Signup registers/binds a Verae central user and stores veraeUserId. Public access stays the zappier API key. Chain JWTs stay server-side behind tokenRef. Authz, billing, and jobs.watch carry veraeUserId.

packages/zappier/src/statement.ts

@@ -4,6 +4,7 @@ import { UsageEntry } from './usage';
 
 export function composeStatement(args: {
   customerId: string;
+  veraeUserId?: string;
   prepaidCents: number;
   credits: CreditAdjustment[];
   usage: UsageEntry[];
@@ -21,6 +22,7 @@ export function composeStatement(args: {
     }));
   return {
     customerId: args.customerId,
+    veraeUserId: args.veraeUserId,
     prepaidCents: args.prepaidCents,
     credits: args.credits.filter((c) => c.customerId === args.customerId),
     usage: args.usage