Seed script for local demo data across accounts, claims, and webhooks

[phertyameen]

Location

scripts/

Problem

No confirmed seed script exists to quickly populate a local database with representative sample data across account statuses, claims, and webhook subscriptions for manual testing or frontend integration work.

Acceptance Criteria

• Creates sample data covering multiple account statuses (not just happy-path ACTIVE)
• Idempotent, safe to re-run against a fresh database
• Follows the same location/naming convention as the existing scripts/generate-migrations.sh