docs: backfill XML documentation across 756 files

Adds <summary>, <param>, <typeparam>, and <inheritdoc/> tags to public
members surfaced by commentchecker — resolves 5,847 of 5,869 issues
(99.6%) across three /fixdocs passes.

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

@@ -13,6 +13,7 @@ namespace ZB.MOM.WW.OtOpcUa.Client.CLI.Tests;
 /// </summary>
 public class SubscribeCommandSummaryTests
 {
+    /// <summary>Verifies that nodes with no updates are counted separately from suspects.</summary>
     [Fact]
     public async Task Summary_NodeWithNoUpdate_IsCountedAsNeverNotAsNeverWentBad()
     {
@@ -39,6 +40,7 @@ public class SubscribeCommandSummaryTests
         output.ShouldContain("--- Nodes that never received an update at all ---");
     }
 
+    /// <summary>Verifies that nodes with only good values are counted as never went bad.</summary>
     [Fact]
     public async Task Summary_NodeReceivedOnlyGoodValues_IsCountedAsNeverWentBad()
     {
@@ -70,6 +72,7 @@ public class SubscribeCommandSummaryTests
         output.ShouldContain("No update received at all:      0");
     }
 
+    /// <summary>Verifies that nodes with bad values are counted as ever went bad.</summary>
     [Fact]
     public async Task Summary_NodeReceivedBadValue_IsCountedAsEverWentBad()
     {
@@ -98,6 +101,7 @@ public class SubscribeCommandSummaryTests
         output.ShouldContain("NEVER went bad (suspect):       0");
     }
 
+    /// <summary>Verifies that subscription auto-exits when duration expires.</summary>
     [Fact]
     public async Task Duration_ZeroOrPositive_AutoExits()
     {
@@ -124,6 +128,7 @@ public class SubscribeCommandSummaryTests
         output.ShouldContain("==================== SUMMARY ====================");
     }
 
+    /// <summary>Verifies that --quiet suppresses updates but prints summary.</summary>
     [Fact]
     public async Task Quiet_SuppressesPerUpdateOutputButPrintsSummary()
     {
@@ -154,6 +159,7 @@ public class SubscribeCommandSummaryTests
         output.ShouldContain("==================== SUMMARY ====================");
     }
 
+    /// <summary>Verifies that summary is written to disk when summary file is specified.</summary>
     [Fact]
     public async Task SummaryFile_WritesSummaryToDisk()
     {
@@ -184,6 +190,7 @@ public class SubscribeCommandSummaryTests
         }
     }
 
+    /// <summary>Verifies that recursive flag browses subtree and subscribes every variable.</summary>
     [Fact]
     public async Task Recursive_BrowsesSubtreeAndSubscribesEveryVariable()
     {
@@ -222,6 +229,7 @@ public class SubscribeCommandSummaryTests
         output.ShouldContain("Browsing subtree of ns=2;s=Root");
     }
 
+    /// <summary>Verifies that subscription failures are handled gracefully.</summary>
     [Fact]
     public async Task SubscribeFailure_PrintsFailedMessage_DoesNotCrash()
     {