fix: use nostr-sdk more wihout breaking changes

[arcbtc]

is much more stable

[motorina0]

LGTM
needs CI fix and testing

[talvasconcelos]

Tested, all works smooth

[dadofsambonzuki]

FYI - I reverted my fixes (PR #71) , which were working with NWC clients, with this change and now it is not working for me.

Investigating ...

[dadofsambonzuki]

Root Cause Found & Fixed

The core bug: the SDK's RelayMessageEnum uses variant EVENT_MSG with method is_EVENT_MSG(), but the code was calling the nonexistent is_EVENT(). Every EVENT message arriving through handle_msg was silently dropped — they never entered the message pool.

This affected any subscription where the response arrives before subscribe_with_id_to registration completes (most notably limit: 1 subscriptions like kind 13194 used by NWC wallets).

Fix

Handled in PR #72 as I don't have access to branches here.

• handle_msg: use is_EVENT_MSG() instead of is_EVENT(), handle OK messages
• handle: add try/except with error logging
• _broadcast_subscription / _replay_cached_subscriptions: register subscriptions via subscribe_with_id_to alongside raw REQ, so events also arrive through the handle callback for ongoing subscriptions