Resolve all 622 issues flagged by the enhanced CommentChecker: add missing
<returns> tags (incl. the standard phrasing on non-generic Task methods),
add missing <summary> tags, and replace misused/redundant <inheritdoc/> on
members that override or implement nothing with real documentation.
Documentation-only — no behavior change; solution builds clean.
Adds IAlarmSubscribableConnection to OpcUaDataConnection, IOpcUaClient alarm
subscription methods, and RealOpcUaClient A&C event monitored-item +
EventFilter + ConditionRefresh snapshot, mapping fields via OpcUaAlarmMapper.
Behavior verified against a live A&C server in Task 28; mapper unit-tested.
Joseph Doherty