docs: add Reports, Email-to-vendor, microservices

Feature-Catalogue.md

@@ -22,6 +22,9 @@ with the detail, or names the code that implements it.
   matching vessel, auto-creating vendor/products/prices.
 - **PDF / XLSX export** — gated to `MGR_APPROVED`+; approver name + signature on
   the document; company details populate the header.
+- **Email PO to vendor** — one-click Outlook draft to the vendor's primary
+  contact with a **7-day download link** to the PO PDF, rendered by the
+  **PdfService** microservice and stored in R2 (issue #14).
 - **Discard draft**, **edit & resubmit**, **edit-highlight diff** on resubmitted
   POs.
 
@@ -61,6 +64,16 @@ with the detail, or names the code that implements it.
 - **SuperUser access requests** — request from profile; resolved at
   `/admin/superuser-requests`.
 
+## Reports (spend analytics)
+
+- **Reports → Purchasing** (`view_analytics` — Manager / SuperUser / Auditor /
+  Admin) — two report families, each index → drill-down → detail:
+  **Cost Centres** (spend across vessels) and **Accounting Codes** (the
+  Heading → Sub → Leaf tree). KPI tiles, comparison + trend charts (one colour
+  per item), Top-N tables, per-row sparklines, and **CSV export**. Filters
+  (granularity Weekly / Monthly / Yearly, financial year, Top/Bottom-N, an
+  “Add to graph” custom comparison) live in the URL. See [Reports](Reports).
+
 ## Operations
 
 - **Report Issue button** — any signed-in user files a Forgejo issue from the
@@ -68,6 +81,10 @@ with the detail, or names the code that implements it.
 - **Automated issue→fix→PR pipeline** + **tag-triggered deploy**. See
   [Issue-to-Deploy Pipeline](Issue-to-Deploy-Pipeline).
 - **Staging instance** against a daily **prod-mirror test DB** for smoke testing.
+- **Microservices** — three standalone Express + Playwright services on pms1:
+  **GstService** (GSTIN lookup), **EpfoService** (UAN/EPFO lookup), **PdfService**
+  (PO→PDF for “Email to vendor”); auto-deployed on release via
+  `ecosystem.config.js`. See [Deployment and Operations](Deployment-and-Operations#microservices).
 
 For the screen-by-screen breakdown, see [Pages and Navigation](Pages-and-Navigation).
 For what shipped recently, see [Changelog](Changelog).