feat(utilities): add domains field for multi-domain tracking (ALL-732) (#206)

* feat(utilities): add domains field for multi-domain tracking

* feat(domains): Add GIN index + backfill script (ALL-732 continued)

- Add GIN index to domains column for efficient array containment queries
- Create backfill script: NRECA/EIA-861 known domains + website fallback
- OpenAPI description: email/web domains for CRM scoping

Backfill script supports:
- Known utility domain mappings (NRECA, EIA-861)
- Website field parsing (extract domain)
- Graceful handling of missing data

Run backfill: `tsx scripts/backfill-utility-domains.ts`

After migration + backfill, /utilities and /utilities/{slug} endpoints
will include domains array for email-scoping and cross-system matching.

* feat(domains): Backfill utility domains from seed + website fallback (ALL-732)

- Add backfill-utility-domains.ts: KNOWN_UTILITY_DOMAINS seed list + NRECA dir support
- Populate 3133 utilities with domains array (prioritizes seed > existing > NRECA > website fallback)
- Add push-utility-domains-to-db.ts: one-shot script to sync data/utilities.json → Neon
- Update package.json with npm run backfill:utility-domains scripts
- Add GIN index on utilities.domains + test suite in drizzle 0004
- OpenAPI: domains array is auto-generated by the generator

This completes the schema (832ddae) + migration (a70318f) already on the branch.

Unblocks Relay + CRM consumers to scope email ingestion by organization.
Closes ALL-732.

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Co-authored-by: texture-coding-agent <coding-agent@texturehq.com>

Author: texture-fleet-agent[bot]

data/utilities.json

@@ -0,0 +1,3 @@
+ALTER TABLE "utilities" ADD COLUMN "domains" text[];--> statement-breakpoint
+-- GIN index for array containment queries (e.g., WHERE domains @> ARRAY['example.com'])
+CREATE INDEX "idx_utilities_domains" ON "utilities" USING GIN("domains");