Sparrow Wallet Release 1.9.1

Introduced support for testnet4 network

• Activate using -n testnet4 option
• Separate storage for config and wallets from testnet3, with copy functionality
• On Linux and macOS, the testnet folder in Sparrow home will be renamed to testnet3 and linked via testnet symlink
• Implemented testnet4 Electrum public server and remote transaction broadcast via mempool.space
• Enhanced gap limit adjustment for PSBT signing when input derivations match an open wallet
• Added optional BBQR format for output descriptor QR export with Coldcard, software, or watch-only keystores
• Refreshed Coldcard import and export instructions to align with latest firmware
• Modified default derivation path for ‘unknown’ Unchained signer

Resolved issues

• Corrected single character multisig output descriptor threshold parsing
• Fixed premature decompression of BBQR zlib components
• Addressed signing regression on PSBTs with external inputs
• Adjusted wallet loading failure icon color in tab label for dark theme compatibility
• Updated Electrum wallet export to use hardware keystore types for USB-capable hardware wallets only