Harden Supabase production sync

[davemorin]

Summary

• default Storage auth config to the current Supabase SUPABASE_SECRET_KEY name while keeping legacy SUPABASE_SERVICE_ROLE_KEY fallback
• ignore local .env.local files for credentials
• add repeatable sync --exclude-table for pathological large tables
• add intra-table row progress and disable Postgres statement_timeout during data copies

Testing

• go test ./...
• generated config smoke check
• git diff --check