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.

packages/zappier/zapier-app/authentication.js

@@ -0,0 +1,23 @@
+module.exports = {
+  type: 'custom',
+  test: (z, bundle) =>
+    z.request({ url: `${bundle.authData.baseUrl}/v1/status` }).then((r) => r.data),
+  fields: [
+    {
+      key: 'baseUrl',
+      label: 'API Base URL',
+      type: 'string',
+      required: true,
+      default: 'http://localhost:3000',
+      helpText: 'Where your Zappier API is running.',
+    },
+    {
+      key: 'apiKey',
+      label: 'API Key',
+      type: 'password',
+      required: true,
+      helpText: 'Your Zappier customer API key.',
+    },
+  ],
+  connectionLabel: '{{bundle.authData.baseUrl}}',
+};