Fix all __init__.py files - add proper exports

snip/sync/__init__.py

@@ -1 +1,6 @@
-"""Sync module for Snip."""
+"""Sync module for P2P discovery and synchronization."""
+
+from .discovery import DiscoveryService
+from .protocol import SyncProtocol
+
+__all__ = ["DiscoveryService", "SyncProtocol"]