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/index.md

@@ -0,0 +1,51 @@
+# `zappier/index`
+
+**Package:** `zappier`  
+**Source:** `packages/zappier/src/index.ts`  
+**Lines:** 42
+
+## What this module is
+
+Implementation module in `zappier`. The tables below are extracted from the source (signatures + JSDoc).
+
+## Exports
+
+_No named `export` / `module.exports` keys detected._
+
+## Types / interfaces / classes
+
+_None extracted._
+
+## Functions
+
+_No top-level functions extracted._
+
+## What it imports / requires
+
+- `path`
+- `better-sqlite3`
+- `dotenv`
+- `./app`
+- `./admin-users`
+- `./billing/reload`
+- `./db/admin-user-repo`
+- `./db/customer-repo`
+- `./db/invoice-repo`
+- `./db/pricing-store`
+- `./db/session-repo`
+- `./db/usage-repo`
+- `./paths`
+- `./portal`
+
+## Call graph (identifiers invoked)
+
+`loadEnv`, `join`, `seeded`, `seedAdminUsersFromEnv`, `immediately`, `hasRealStripeKey`, `stripePaymentClient`, `async`, `buildApp`, `listen`, `log`
+
+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`.
+