feat(channels): wire up email channel (IMAP/SMTP) into config and registration

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/daemon/mod.rs

@@ -210,6 +210,8 @@ fn has_supervised_channels(config: &Config) -> bool {
         || config.channels_config.slack.is_some()
         || config.channels_config.imessage.is_some()
         || config.channels_config.matrix.is_some()
+        || config.channels_config.whatsapp.is_some()
+        || config.channels_config.email.is_some()
 }
 
 #[cfg(test)]