made a thing: Signet - a native remote signer for nostr. your key lives encrypted (NIP-49) inside a small daemon on your machine. apps request signatures over NIP-46, and every single request waits for an explicit approve/deny in a native macOS app. the key never enters the GUI, let alone a client. works over public relays, including ones behind NIP-42 auth. 
GitHub
GitHub - zig-nostr/signet: Signet — a native remote signer (NIP-46 bunker) for Nostr. Your key stays on a machine you control; every signing request waits for your approval. Built on zig-nostr/nostr.
Signet — a native remote signer (NIP-46 bunker) for Nostr. Your key stays on a machine you control; every signing request waits for your approval...