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.AbLegacy.Tests/AbLegacyReadWriteTests.cs

@@ -23,6 +23,7 @@ public sealed class AbLegacyReadWriteTests
     // ---- Read ----
 
     /// <summary>Verifies that an unknown reference maps to BadNodeIdUnknown.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Unknown_reference_maps_to_BadNodeIdUnknown()
     {
@@ -34,6 +35,7 @@ public sealed class AbLegacyReadWriteTests
     }
 
     /// <summary>Verifies that a successful N-file read returns a Good status.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Successful_N_file_read_returns_Good_value()
     {
@@ -51,6 +53,7 @@ public sealed class AbLegacyReadWriteTests
     }
 
     /// <summary>Verifies that repeated reads reuse the runtime.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Repeat_read_reuses_runtime()
     {
@@ -67,6 +70,7 @@ public sealed class AbLegacyReadWriteTests
     }
 
     /// <summary>Verifies that non-zero libplctag status values map via AbLegacyStatusMapper.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task NonZero_libplctag_status_maps_via_AbLegacyStatusMapper()
     {
@@ -82,6 +86,7 @@ public sealed class AbLegacyReadWriteTests
     }
 
     /// <summary>Verifies that read exceptions surface as BadCommunicationError.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Read_exception_surfaces_BadCommunicationError()
     {
@@ -96,6 +101,7 @@ public sealed class AbLegacyReadWriteTests
     }
 
     /// <summary>Verifies that batched reads preserve order.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Batched_reads_preserve_order()
     {
@@ -120,6 +126,7 @@ public sealed class AbLegacyReadWriteTests
     }
 
     /// <summary>Verifies that read tag creation parameters are composed from device and profile.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Read_TagCreateParams_composed_from_device_and_profile()
     {
@@ -140,6 +147,7 @@ public sealed class AbLegacyReadWriteTests
     // ---- Write ----
 
     /// <summary>Verifies that a non-writable tag rejects with BadNotWritable.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Non_writable_tag_rejects_with_BadNotWritable()
     {
@@ -153,6 +161,7 @@ public sealed class AbLegacyReadWriteTests
     }
 
     /// <summary>Verifies that a successful N-file write encodes and flushes the data.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Successful_N_file_write_encodes_and_flushes()
     {
@@ -169,6 +178,7 @@ public sealed class AbLegacyReadWriteTests
     }
 
     /// <summary>Verifies that bit-within-word write now succeeds via RMW.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Bit_within_word_write_now_succeeds_via_RMW()
     {
@@ -190,6 +200,7 @@ public sealed class AbLegacyReadWriteTests
     }
 
     /// <summary>Verifies that write exceptions surface as BadCommunicationError.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Write_exception_surfaces_BadCommunicationError()
     {
@@ -204,6 +215,7 @@ public sealed class AbLegacyReadWriteTests
     }
 
     /// <summary>Verifies that batch write preserves order across different outcomes.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Batch_write_preserves_order_across_outcomes()
     {
@@ -233,6 +245,7 @@ public sealed class AbLegacyReadWriteTests
     }
 
     /// <summary>Verifies that cancellation propagates through the driver.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Cancellation_propagates()
     {
@@ -250,6 +263,7 @@ public sealed class AbLegacyReadWriteTests
     }
 
     /// <summary>Verifies that ShutdownAsync disposes all runtimes.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ShutdownAsync_disposes_runtimes()
     {