docs: complete XML doc coverage (returns, summaries, inheritdoc)

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.

src/ZB.MOM.WW.ScadaBridge.CLI/Commands/DebugStreamHelpers.cs

@@ -27,6 +27,7 @@ internal static class DebugStreamHelpers
     /// </summary>
     /// <param name="ex">The exception thrown by HubConnection.StartAsync.</param>
     /// <param name="cancellationRequested">True when the user requested cancellation (Ctrl+C) before the exception was thrown.</param>
+    /// <returns>A <see cref="ConnectFailure"/> describing whether the failure was a cancellation and the appropriate exit code.</returns>
     internal static ConnectFailure ClassifyConnectFailure(Exception ex, bool cancellationRequested)
     {
         if (cancellationRequested && ex is OperationCanceledException)
@@ -43,6 +44,7 @@ internal static class DebugStreamHelpers
     /// result is ever produced (pure Ctrl+C), the stream ended gracefully — exit 0.
     /// </summary>
     /// <param name="exitTask">The task whose result is the intended exit code, set by OnStreamTerminated or the Closed handler.</param>
+    /// <returns>A task that resolves to the process exit code (0 for graceful exit or pure Ctrl+C, non-zero for error).</returns>
     internal static async Task<int> ResolveStreamExitCodeAsync(Task<int> exitTask)
     {
         if (exitTask.IsCompletedSuccessfully)