docs: complete XML doc comments via fixdocs (2757 to 131 findings)

Add missing <returns>/<param>/<summary>/<typeparam> tags and clean up
misused inheritdoc across 481 files so the documented API surface is
complete. Documentation-only (zero code lines changed). The 131 remaining
findings are inheritdoc-style warnings deliberately left to preserve
hand-written implementation rationale (plan-decision notes, race-condition
explanations).

tests/Client/ZB.MOM.WW.OtOpcUa.Client.CLI.Tests/SubscribeCommandSummaryTests.cs

@@ -14,6 +14,7 @@ namespace ZB.MOM.WW.OtOpcUa.Client.CLI.Tests;
 public class SubscribeCommandSummaryTests
 {
     /// <summary>Verifies that nodes with no updates are counted separately from suspects.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Summary_NodeWithNoUpdate_IsCountedAsNeverNotAsNeverWentBad()
     {
@@ -41,6 +42,7 @@ public class SubscribeCommandSummaryTests
     }
 
     /// <summary>Verifies that nodes with only good values are counted as never went bad.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Summary_NodeReceivedOnlyGoodValues_IsCountedAsNeverWentBad()
     {
@@ -73,6 +75,7 @@ public class SubscribeCommandSummaryTests
     }
 
     /// <summary>Verifies that nodes with bad values are counted as ever went bad.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Summary_NodeReceivedBadValue_IsCountedAsEverWentBad()
     {
@@ -102,6 +105,7 @@ public class SubscribeCommandSummaryTests
     }
 
     /// <summary>Verifies that subscription auto-exits when duration expires.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Duration_ZeroOrPositive_AutoExits()
     {
@@ -129,6 +133,7 @@ public class SubscribeCommandSummaryTests
     }
 
     /// <summary>Verifies that --quiet suppresses updates but prints summary.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Quiet_SuppressesPerUpdateOutputButPrintsSummary()
     {
@@ -160,6 +165,7 @@ public class SubscribeCommandSummaryTests
     }
 
     /// <summary>Verifies that summary is written to disk when summary file is specified.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task SummaryFile_WritesSummaryToDisk()
     {
@@ -191,6 +197,7 @@ public class SubscribeCommandSummaryTests
     }
 
     /// <summary>Verifies that recursive flag browses subtree and subscribes every variable.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Recursive_BrowsesSubtreeAndSubscribesEveryVariable()
     {
@@ -230,6 +237,7 @@ public class SubscribeCommandSummaryTests
     }
 
     /// <summary>Verifies that subscription failures are handled gracefully.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task SubscribeFailure_PrintsFailedMessage_DoesNotCrash()
     {