Milestone 0: import zappier billing, Verae middleware, and Zapier research

Compose-ready workspace: packages/zappier (rate card, portal, Stripe),
packages/verae-zapier-middleware (timestamp + NATS), packages/verae-zapier
(CLI app), vendor/zapier-platform, and research/zapier vendor corpus.

Gate 0 structure checks pass. Product code and research are not yet wired.

vendor/zapier-platform/example-apps/digest-auth/middleware.js

@@ -0,0 +1,19 @@
+'use strict';
+
+// This function runs after every outbound request. You can use it to check for
+// errors or modify the response. You can have as many as you need. They'll need
+// to each be registered in your index.js file.
+const handleBadResponses = (response, z, bundle) => {
+  if (response.status === 401) {
+    throw new z.errors.Error(
+      // This message is surfaced to the user
+      'The username and/or password you supplied is incorrect',
+      'AuthenticationError',
+      response.status,
+    );
+  }
+
+  return response;
+};
+
+module.exports = { befores: [], afters: [handleBadResponses] };