feat(admin): analytics dashboard

Sprint 27.

New features/admin/analytics/ module + net-new /:lang/backoffice/analytics
route + Dashboard Quick Action.

- revenue/orders/avg-order-value/sales-over-time/top-products computed by
  composing AdminOrdersLocalGateway (Sprint 23's seeded mock orders) - real
  aggregation over mock data, not a separate fabricated dataset
- products/categories counts from AdminProductsLocalGateway/
  AdminCategoriesLocalGateway
- visitors/funnels/heatmaps render pending-backend badges (no analytics
  pipeline exists anywhere in this system) rather than fabricated numbers,
  same convention as the Sprint 19 dashboard's pre-Sprint-23 Orders/Revenue
  cards
- plain div-bar chart (no charting library), 7/30/90-day range toggle,
  CSV export

docs/ADMIN.md + docs/BACKEND.md (new item 16) updated.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

docs/ADMIN.md

@@ -391,6 +391,31 @@ routes at all, this is a net-new admin section.
   audit and Sprint 25's per-user audit. No consolidation attempted - they
   track different things.
 
+## Sprint 27 - Analytics
+
+`features/admin/analytics/`, net-new `/​:lang/backoffice/analytics` route
++ Dashboard Quick Action.
+
+- **Real, derived data**: revenue/orders/avg-order-value/sales-over-time
+  chart/top-products are computed by composing the existing
+  `AdminOrdersLocalGateway` (Sprint 23's seeded mock orders) - not a
+  separate fabricated dataset. Products/Categories counts come from
+  `AdminProductsLocalGateway`/`AdminCategoriesLocalGateway`. All of this is
+  still ultimately backed by mock order/product/category data (per those
+  sprints), but the *aggregation* is real arithmetic over that data, not
+  invented numbers.
+- **Visitors, funnels, heatmaps**: no analytics/tracking pipeline exists
+  anywhere in this codebase, so these render an explicit
+  "Awaiting backend integration" (`pending-backend`) badge, same convention
+  as the Sprint 19 dashboard's Orders/Revenue cards before Sprint 23 -
+  not fabricated numbers, not a generic empty state.
+- **Chart**: a plain inline `<div>`-bar chart driven by `[style.height.%]`,
+  no charting library pulled in - reasonable for one sales-over-time series
+  at this scale; revisit if more chart types are actually needed.
+- **Date ranges**: 7/30/90-day toggle filters orders by `createdAt`.
+- **Export**: CSV of the sales series (client-side `Blob` download, same
+  pattern as Orders/Transactions).
+
 ## Known gaps / backend needs
 
 - **Dashboard metrics endpoint.** Categories/Products counts are computed

docs/BACKEND.md

@@ -168,6 +168,14 @@ Plus, if authenticated history/wishlist/compare/saved-searches sync is wanted: `
 
 **Frontend files:** implement `AdminMonitoringApiGateway`-equivalent methods against a to-be-defined `AdminMonitoringGateway` interface (`AdminMonitoringLocalGateway` currently has no interface extracted — add one when a real implementation is built, mirroring the pattern used everywhere else in `admin/*`).
 
+## 16. Analytics - visitors/funnels/heatmaps (Sprint 27, no backend at all)
+
+**Current behavior:** `features/admin/analytics/` computes real revenue/orders/top-products aggregations from the existing mock order data (see item 7), but visitor traffic, conversion funnels, and heatmaps have zero data source anywhere in this system (no analytics/tracking pipeline, no event collection) — these render `pending-backend` badges rather than fabricated numbers.
+
+**Needed:** a traffic/event tracking pipeline (page views, sessions, conversion events) and a funnel/heatmap aggregation service, before this section of the Analytics page can show anything real.
+
+**Frontend files:** `features/admin/analytics/pages/admin-analytics-page.component.html` currently renders the pending-backend badge inline (no gateway method exists for this yet, unlike every other mocked domain in this doc).
+
 ## Known reliability issues
 
 ### Production 502/504 Bad Gateway on refresh / back-navigation

docs/SPRINT-PLAN.md

@@ -64,8 +64,9 @@ Notify user: **from Sprint 20 (Categories) once product↔category link + admin
 - [x] `docs/ADMIN.md` (new Sprint 26 section), `docs/BACKEND.md` item 15 added
 - Commit: `feat(admin): monitoring center`
 
-## Sprint 27 — Analytics
-- [ ] Dashboard extensions: sales/revenue/orders/visitors/products/categories charts, date ranges, export
+## Sprint 27 — Analytics ✅ done
+- [x] Sales/revenue/orders/products/categories (real aggregation over mock order data), visitors/funnels/heatmaps (pending-backend badges, no fabricated data), sales-over-time bar chart, 7/30/90-day ranges, CSV export
+- [x] `docs/ADMIN.md` (new Sprint 27 section), `docs/BACKEND.md` item 16 added
 - Commit: `feat(admin): analytics dashboard`
 
 ## Sprint 28 — Marketplace Polish