Fleet now spawns the real zappier and middleware processes. Metered
timestamp/receipt/hash calls proxy to middleware when ZAPPIER_UPSTREAM
is set. CS credits, sales per-customer pricing, and QuickBooks export
are separate repos plugged into zappier-edge admin.
In-process trace console validates hops, faults, recoveries, and
suggested changes before zapier-platform push. User guide covers
signup through central-chain and bulk-summary tree-node hash lookup.
