[rem1niscence]

Description

Validates keystore nicknames on import. A nickname is now required and may only contain letters, digits, - and _.

Related Issues

Closes: #N/A

Changes Made

• Added crypto.ValidateNickname(), backed by the ^[a-zA-Z0-9_-]+$ regex
• Added tests for valid and invalid nicknames, and for both import paths rejecting bad input without changing the keystore

Checklist

• I have tested the changes locally and verified they work as intended.
• I have appropriately titled my branch issue-#<issue-number>.
• I have run re-built the web-wallet and/or block explorer (if applicable).
• I have run npm run prettier to format the web-wallet and/or block explorer (if applicable)
• I have updated documentation (if applicable).
• I have included tests for the changes (if applicable).

Additional Notes

Breaking change: imports with an empty nickname now fail. Callers that relied on importing keys without a nickname (CLI keystore-import, keystore-import-raw, keystore-new-key, and the wallet) must now provide a valid one. Nicknames already stored in a keystore are not re-validated.