keyrx 0.3.0

• grind --passphrase — a BIP39 passphrase (the "25th word"). Prompted on the terminal, hidden, typed
  twice; never read from a flag, a file or the environment; never stored, never printed. The grind
  derives every candidate from PBKDF2(mnemonic, "mnemonic" + passphrase), exactly as every wallet
  that takes one does. The match file gains one line under the seed — passphrase used - NOT stored: the seed alone will not reach this address; the keys will — the fact, never the passphrase; show
  marks such matches; the MATCH panel and the GRIND panel say so. Most browser wallets have no
  passphrase field on seed import: import the KEY, which is standalone.
• keyrx verify now also checks the passphrase path against the BIP39 specification's first test
  vector ("abandon … about" + "TREZOR" → the published seed), pinned; and the manual cross-check note
  says what to type at solana-keygen's prompt for a passphrase grind.
• Minor version bump because the match file format gained a line (older show ignores it).