Yield-bearing allowance, on-chain. Inspired by the Brazilian décimo terceiro (the 13th-month salary). Seedling teaches kids patience compounds. Parents deposit USDC once; the vault earns ~8% APY on Kamino; kids get a monthly allowance plus a year-end bonus from accumulated yield. We reward patience, not consumerism. While Greenlight charges $240/yr, Seedling charges nothing, we share 10% of yield. Parent-custody is architecturally enforced: the kid never holds a key.