Edges/device-config headline/state path audit

Artem-requested evidence-only audit on 2026-08-05: verify packages/edges/src/config/entities.ts headline metric paths and state fieldPaths against device GraphQL schema, production TimescaleDB values, and packages/device-config. No code changes. Critical finding: inverter.primary expects uppercase GridStatus but GraphQL returns lowercase, so mapping misses all values. Reported to Artem in Slack DM.