Replace insecure raw-pubkey auth with cryptographic NIP-98 signed
requests and server-issued JWT sessions. Logout now fully clears
all state including nsec. Add yellow "Use Nostr Signer" button
for Amber/NIP-07 remote signers.
- Server: JWT middleware (HMAC-SHA256, 24h expiry), NIP-98 verification
- Server: POST /api/auth/nostr/session endpoint
- Frontend: NIP-98 token builder + authFetch wrapper with JWT Bearer
- Frontend: All authenticated API calls use authFetch
- Security: logout clears JWT, pubkey, bot, nsec, and profile pic
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
