Vault

examples/vault/programs/vault.py holds lamports on a PDA whose seed is the literal vault. deposit calls system_transfer from the authority and adds the amount to balance. close checks the authority, then CloseTo returns the lamports after the body succeeds.

The account is 49 bytes: discriminator, authority at offset 8, balance at 40, bump at 48. This vault is not the fixture program under tests/fixtures, which uses the seed box.