fix(cli): resolve CLI-008..013 — format validation, exit-code semantics, debug-stream cancellation/disposal, test coverage

src/ScadaLink.CLI/Commands/DebugCommands.cs

@@ -94,7 +94,8 @@ public static class DebugCommands
             .WithAutomaticReconnect()
             .Build();
 
-        var cts = new CancellationTokenSource();
+        // CLI-011: CancellationTokenSource owns a WaitHandle and must be disposed.
+        using var cts = new CancellationTokenSource();
         var exitTcs = new TaskCompletionSource<int>(TaskCreationOptions.RunContinuationsAsynchronously);
 
         Console.CancelKeyPress += (_, e) =>
@@ -192,8 +193,18 @@ public static class DebugCommands
         }
         catch (Exception ex)
         {
+            // CLI-010: Ctrl+C during connect throws OperationCanceledException — that is
+            // a graceful user cancellation, not a connection failure.
+            var failure = DebugStreamHelpers.ClassifyConnectFailure(ex, cts.IsCancellationRequested);
+            if (failure.IsCancellation)
+            {
+                await connection.DisposeAsync();
+                return failure.ExitCode;
+            }
+
             OutputFormatter.WriteError($"Connection failed: {ex.Message}", "CONNECTION_FAILED");
-            return 1;
+            await connection.DisposeAsync();
+            return failure.ExitCode;
         }
 
         try
@@ -232,7 +243,11 @@ public static class DebugCommands
         }
 
         await connection.DisposeAsync();
-        return exitTcs.Task.IsCompletedSuccessfully ? exitTcs.Task.Result : 0;
+
+        // CLI-012: resolve the exit code from a single authoritative source. A result
+        // set by OnStreamTerminated/Closed always wins; a brief grace period covers a
+        // termination racing with Ctrl+C. Pure Ctrl+C (no result) is a graceful exit 0.
+        return await DebugStreamHelpers.ResolveStreamExitCodeAsync(exitTcs.Task);
     }
 
     private static void PrintSnapshotTable(JsonElement snapshot)