Add db-dump and db-migrate scripts to strip \restrict lines

PostgreSQL 17.6+ adds random \restrict/\unrestrict tokens to pg_dump
output (CVE-2025-8714 security fix), causing schema.sql to appear
changed on every dump even when the schema hasn't changed.

These wrapper scripts run dbmate and strip the \restrict lines from
the output to keep schema.sql stable.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

README.md

@@ -111,6 +111,8 @@ bun run dev
 | `bun run lint:fix` | Fix linting issues |
 | `bun run test` | Run tests |
 | `bun run db:codegen` | Generate database types |
+| `./scripts/db-dump` | Dump database schema (strips `\restrict` lines) |
+| `./scripts/db-migrate` | Run migrations (strips `\restrict` lines) |
 
 ## CLI