Blockle 0.2.2 — full wallet management

Everything you expect from a Bitcoin Core wallet, on post-quantum keys: passphrase encryption (scrypt + ChaCha20-Poly1305; locked wallets still receive and render), unlock-for-session, change-passphrase, wallet backup, portable key export/import, and message signing/verification — in the CLI (blockle-chain wallet …) and in the Qt wallet's new Wallet tab. Also hardens concurrent wallet access (atomic writes) and headless passphrase handling.