feat(monitoring): observability stack + app instrumentation

- /health/ready (DB+MinIO+Casdoor checks, webhook post-deploy gate),
  /metrics via prometheus-fastapi-instrumentator, Sentry/GlitchTip capture,
  X-Request-ID middleware + JSON access logging (PROCUREMENT_LOG_FORMAT)
- server-side analytics (OpenPanel Track API): login, quote lifecycle,
  receipts — fire-and-forget, disabled without env config
- monitoring/ compose project: GlitchTip(+pg), Prometheus(+alerts),
  Grafana(provisioned ERP dashboard), Loki+Promtail, node/postgres
  exporters, cAdvisor — mem-limited (~2.2GB), loopback admin UIs,
  separate from app deploys; erp_shared network for scraping
- frontend: @openpanel/web + @sentry/react (build-arg gated, no-op when
  unset), funnel events (login, wizard steps, quote submitted)
- compose: api healthcheck, observability env wiring, .env.example keys

backend/app/routers/pm.py

@@ -50,6 +50,7 @@ from app.models.procurement import (
     Supplier,
 )
 from app.schemas.procurement import PMReceiptCreate
+from app.services import analytics
 from app.services.inventory_service import canonical_specs_hash
 from app.utils.errors import (
     ForbiddenError,
@@ -429,6 +430,16 @@ async def pm_confirm_receipt(
             quote.arrived_date = payload.received_at
 
     item_state = arrival_state(li.quantity, already_received + payload.received_qty)
+    await analytics.track(
+        "receipt_confirmed",
+        {
+            "receipt_id": str(receipt.id),
+            "quote_id": str(quote.id),
+            "quantity": str(payload.received_qty),
+            "state": item_state,
+        },
+        profile_id=ctx.display_name,
+    )
     return {"data": {
         "receipt_id": str(receipt.id),
         "state": item_state,