fix(db): add missing 0021 drizzle snapshot to eliminate generate drift

Commit notes

The drizzle/meta/ folder only had snapshots for a subset of migrations (0000, 0004, 0008, 0011, 0020), so the newest snapshot lagged the newest migration (0021_stripe_migration). Because `drizzle-kit generate` diffs schema.ts against the latest snapshot on disk, the next `db:generate` would re-surface everything migration 0021 already did (the mollie -> stripe transition) as a phantom pending migration.

Generate the 0021 snapshot from schema.ts via drizzle-kit's own serializer (generateDrizzleJson), chained onto 0020's id, instead of hand-editing the 170KB+ JSON. Verified: - `drizzle-kit generate` -> "No schema changes, nothing to migrate" - `drizzle-kit check` -> "Everything's fine"

Does not affect db:migrate or tests (snapshots are only used by generate/push). The remaining historical gaps (0001-0019 hand-written migrations) are not needed: generate only reads the latest snapshot and validation only flags malformed snapshots or prevId collisions, not gaps.