persona signer v0.2.0 (unpacked, developer mode only)

1. Add nsec export
2. Fix a real blank-error bug in the approval flow

persona signer v0.1.0 (unpacked, developer mode only)

▎ First build of the persona NIP-07 browser-extension signer. No Chrome Web Store or Firefox listing yet — this is a
zip for loading unpacked in Developer mode (chrome://extensions → Developer mode → Load unpacked → the extracted
folder).

▎ What works: multi-persona support, passphrase-encrypted storage, getPublicKey/signEvent with a real approval popup
on every call. Try it live at https://solemn.network/try-signer once loaded.

▎ Not yet: Firefox, a signed/store-distributed package, NIP-46 remote signing.