M5: Resolver sanity fixture + CI test

Spec: TextureHQ/mono#10142, task M5. Fixture of ~30 known co-op names mapped to expected eia_id (including Vermont Electric Cooperative -> 19791, edge cases like short names 'ACE' / 'PACE' / 'GRACE' that shouldn't cross-match). Vitest/pgTAP assertion: >= 90% recall at confidence >= 0.90, 0 false positives at that threshold. Publishes precision/recall numbers so threshold decision (0.85 vs 0.90) can be locked on real data. Blocks on M3+M4.