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/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbCip.IntegrationTests/AbCipReadSmokeTests.cs

@@ -21,6 +21,7 @@ public sealed class AbCipReadSmokeTests
 
     /// <summary>Verifies that the driver can read a seeded DInt value from an AB server.</summary>
     /// <param name="profile">The AB server profile to test against.</param>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [AbServerTheory]
     [MemberData(nameof(Profiles))]
     public async Task Driver_reads_seeded_DInt_from_ab_server(AbServerProfile profile)

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbCip.IntegrationTests/AbServerFixture.cs

@@ -55,9 +55,11 @@ public sealed class AbServerFixture : IAsyncLifetime
         }
     }
 
-    /// <inheritdoc />
+    /// <summary>Initializes the fixture asynchronously (no-op for this fixture).</summary>
+    /// <returns>A completed value task.</returns>
     public ValueTask InitializeAsync() => ValueTask.CompletedTask;
-    /// <inheritdoc />
+    /// <summary>Disposes the fixture asynchronously (no-op for this fixture).</summary>
+    /// <returns>A completed value task.</returns>
     public ValueTask DisposeAsync() => ValueTask.CompletedTask;
 
     /// <summary>
@@ -65,6 +67,7 @@ public sealed class AbServerFixture : IAsyncLifetime
     ///     <see cref="AbServerFactAttribute"/> / <see cref="AbServerTheoryAttribute"/>
     ///     to decide whether to skip tests on a fresh clone without a running container.
     /// </summary>
+    /// <returns><see langword="true"/> if the server is reachable; <see langword="false"/> otherwise.</returns>
     public static bool IsServerAvailable() =>
         TcpProbe(ResolveHost(), ResolvePort());
 

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbCip.IntegrationTests/Emulate/AbCipEmulateAlmdTests.cs

@@ -40,6 +40,7 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.AbCip.IntegrationTests.Emulate;
 public sealed class AbCipEmulateAlmdTests
 {
     /// <summary>Verifies that real ALMD raise fires OnAlarmEvent through the driver projection.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [AbServerFact]
     public async Task Real_ALMD_raise_fires_OnAlarmEvent_through_the_driver_projection()
     {

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbCip.IntegrationTests/Emulate/AbCipEmulateUdtReadTests.cs

@@ -38,6 +38,7 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.AbCip.IntegrationTests.Emulate;
 public sealed class AbCipEmulateUdtReadTests
 {
     /// <summary>Verifies that reading a whole UDT decodes each member at its template object offset.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [AbServerFact]
     public async Task WholeUdt_read_decodes_each_member_at_its_Template_Object_offset()
     {