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.

docs/03-zapier/auth.md

@@ -0,0 +1,17 @@
+# Zapier authentication
+
+## Target (after PR 5)
+
+- Type: custom / API key.
+- Fields: `apiKey`, `baseUrl` (default public zappier origin).
+- Header: `x-api-key`.
+- Test: `GET /v1/status` or `GET /v1/me` if added.
+- Errors: 401 invalid key; 403/402 quota or unpriced endpoint → user-visible upgrade text pointing at `/portal`.
+
+## Today (imported CLI app)
+
+- Bearer middleware API key `zmw_…`.
+- Test: `GET /zapier/v1/auth/me`.
+- `afterResponse` maps 402 and `PLAN_UPGRADE_REQUIRED`.
+
+Do not send Verae JWTs to Zapier. Middleware (or zappier→middleware) logs into Verae server-side.