README: document operator_spend_usd in the metrics snapshot

README.md

@@ -108,8 +108,12 @@ Three jobs run inside the container via `CloudronManifest.json` → `addons.sche
 - **metrics_snapshot** (nightly 3:15am) — `metrics_snapshot.py` records one row per
   day into the `metrics_daily` table: members, newsletter subscribers, Matrix
   membership, spend, request counts, and energy/CO₂. A source that cannot be read
-  yields NULL for that metric rather than a zero. `--backfill` rebuilds history
-  idempotently. Methodology: [Energy and carbon metrics](docs/energy-metrics.md).
+  yields NULL for that metric rather than a zero. `spend_usd` is the co-op-wide
+  total and deliberately spans every team, the co-op's own operator accounts
+  included; `operator_spend_usd` is the breakout of that portion, served through
+  `/broker/metrics` so the member dashboard can show the co-op's own share
+  alongside the total. `--backfill` rebuilds history idempotently. Methodology:
+  [Energy and carbon metrics](docs/energy-metrics.md).
 
 Verify after any manifest change: the deploy log must show
 `setupAddons: ... scheduler ...` listing all three tasks, and each script must