Day-to-day ISO risk intelligence (ercot-brief.sh)

Founder ruling 2026-09-06: Base Power must remain the retail provider (no direct ERCOT interconnection). So the ISO's signals are RISK INTELLIGENCE, not an export market:

• ercot-brief.sh produces a daily risk level from LZ_SOUTH RTM (now + 24h peak): GREEN (<$150/MWh) / WATCH (>=150) / ELEVATED (>=500) / CRITICAL (>=2000, adders/EEA territory).
• Actions it emits: precharge battery (WATCH+), defer class-3 batch load (ELEVATED+), rtw_counterfactual_flag (RTM > $85).
• On EEA-watch days expect Base to dispatch the fleet battery and expect RTW-plan counterfactual spikes — history TSV accumulates for trend stats.
• Same source chain as the arbitrage tool (GRIDSTATUS_API_KEY / ERCOT_API_KEY / override — key registration still pending, see #826/#827).