Telemetry spine: add per-circuit monitoring (Emporia, #623) as load-side source (#826)

https://projects.knownelement.com/issues/826#note-9

docs/ARCHITECTURE.md

@@ -106,6 +106,13 @@ Directions:
   needs a metered PDU. UPS re-cabling plan (switches+tsys6/7 on the
   un-metered UPS, everything else on the metered one) is compatible: the
   nodes losing wall-meter visibility are exactly the RAPL/iDRAC nodes.
+- **Load-side telemetry = per-circuit monitoring (#623, Emporia Vue 3
+  pending founder pick)**: per-circuit watts via the HA LOCAL (HACS)
+  integration → knelperf textfile exporter → the class-3 batch gate gets a
+  real deferrable-load menu (server-room subpanel vs HVAC vs site-2
+  equipment). Dedicated CTs on the server-room subpanel + the tsys6/7 UPS
+  legs keep fleet draw separable from house load — needed exactly on EEA
+  days, so local (non-cloud) telemetry matters.
 
 ## 6. Workload priority classes (founder-set order)