Milestone 2: module/model docs (MD, Sphinx RST, PDF) and work log

74 source modules documented with extracted signatures, JSDoc params,
imports, and call graphs. 10 first-class models (PriceRule through
StatusResponse) have their own MD/RST/PDF. Sphinx HTML builds from
docs/sphinx. Per-module PDFs in docs/modules-pdf and docs/models-pdf.

Middleware gates 2–6 and 10 pass on MOCK_VERAE without NATS.

Learned: RST includes are relative to the RST file; keep one PDF per
module; Add Numbers remains the only push required tomorrow.

docs/sphinx/modules/zappier/app.md

@@ -0,0 +1,59 @@
+# `zappier/app`
+
+**Package:** `zappier`  
+**Source:** `packages/zappier/src/app.ts`  
+**Lines:** 203
+
+## What this module is
+
+Implementation module in `zappier`. The tables below are extracted from the source (signatures + JSDoc).
+
+## Exports
+
+`StoredItem`, `DEFAULT_CUSTOMERS`, `AppDeps`, `buildApp`
+
+## Types / interfaces / classes
+
+| Kind | Name |
+|------|------|
+| interface | `StoredItem` |
+| interface | `AppDeps` |
+
+## Functions
+
+| Name | Parameters | Param types (JSDoc) | Returns | Calls (same file / helpers) |
+|------|------------|---------------------|---------|-----------------------------|
+| `buildApp` | `deps: AppDeps = {}` | — | `unknown` | see Call graph |
+
+## What it imports / requires
+
+- `path`
+- `crypto`
+- `express`
+- `express-openapi-validator`
+- `swagger-ui-express`
+- `yamljs`
+- `./auth`
+- `./meter`
+- `./billing/credit`
+- `./pricing`
+- `./usage`
+- `./admin`
+- `./admin-users`
+- `./accounts`
+- `./invoicing`
+- `./paths`
+- `./portal`
+
+## Call graph (identifiers invoked)
+
+`join`, `next`, `parse`, `status`, `json`, `buildApp`, `seeded`, `seedAdminUsersFromEnv`, `rateCard`, `getRateCard`, `tiers`, `getTiers`, `express`, `use`, `load`, `setup`, `adminLoginRouter`, `adminAuth`, `adminRouter`, `static`, `async`, `import`, `toDataURL`, `portalRouter`, `apiKeyAuth`, `middleware`, `get`, `meter`, `post`, `toUpperCase`, `isFinite`, `randomUUID`, `map`, `toISOString`, `unshift`, `filter`, `setUTCDate`, `setUTCHours`, `summaryFor`, `find`, `applyMonthlyCredit`
+
+Each identifier is a call site in this file. Follow the import list to see the defining module; open that module’s MD for parameter and return types.
+
+## Return values (how to read this)
+
+- HTTP route handlers return Express `res.json(...)` bodies (see route docs).
+- Zapier `perform` functions return a **single object** (creates) or an **array** (triggers/searches).
+- Pricing functions return integer **cents** on `Quote.totalCents`.
+