Adds the stealth lock/claim provers; all binaries built against the pinned confidential guest.
A native note's owner is keccak(nk ‖ dom), so a sender cannot mint a spendable note for a third
party: choosing nk keeps spend authority with the sender, and deriving the owner from a pubkey
mints a note nobody can spend. The stealth path escrows to a one-time key instead, and the
recipient claims it into a note under an nk only they can derive — the sound way to pay someone.
New: exec-stealthlock, exec-stealthclaim, exec-stealthrefund, exec-stealthlockbatch,
exec-bridgestealthmint.
The 19 binaries from v5 and bitcoin_prove are byte-identical to that release.
Verified: pinned guest ELF sha256 170504091f44dcaff09ee844e78e446244078fef687eeacf6e61378961e5bba0
derives program_vkey 0x00711089f0dc47b5512aae81461535cfd754ecbaec86dc88dc821c3ef1f4c0a4, which is
present in the live pool's runtime bytecode; every binary here was byte-checked to embed exactly
that ELF, before and after stripping and again after transfer.