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.S7.Tests/S7DriverCodeReviewFixTests.cs

@@ -18,6 +18,7 @@ public sealed class S7DriverCodeReviewFixTests
 
     /// <summary>Verifies that initialize rejects timer or counter tags with NotSupportedException.</summary>
     /// <param name="address">The S7 Timer or Counter address to test.</param>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Theory]
     [InlineData("T0")]
     [InlineData("T15")]
@@ -48,6 +49,7 @@ public sealed class S7DriverCodeReviewFixTests
     }
 
     /// <summary>Verifies that initialize accepts DB and MIQ addresses without triggering the unsupported guard.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Initialize_accepts_DB_and_MIQ_addresses_without_the_unsupported_guard_tripping()
     {
@@ -75,6 +77,7 @@ public sealed class S7DriverCodeReviewFixTests
     // ---- Driver.S7-011 — driverConfigJson must be applied on Initialize ----
 
     /// <summary>Verifies that initialize applies the supplied driverConfigJson over constructor options.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Initialize_applies_the_supplied_driverConfigJson_over_the_constructor_options()
     {
@@ -101,6 +104,7 @@ public sealed class S7DriverCodeReviewFixTests
     }
 
     /// <summary>Verifies that initialize rejects a timer tag supplied only through driverConfigJson.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Initialize_rejects_a_timer_tag_supplied_only_through_driverConfigJson()
     {
@@ -120,6 +124,7 @@ public sealed class S7DriverCodeReviewFixTests
     }
 
     /// <summary>Verifies that reinitialize applies a changed driverConfigJson.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Reinitialize_applies_a_changed_driverConfigJson()
     {
@@ -142,6 +147,7 @@ public sealed class S7DriverCodeReviewFixTests
     // ---- Driver.S7-006 — Shutdown drains probe/poll loops before disposing the gate ----
 
     /// <summary>Verifies that shutdown completes cleanly with active subscriptions and no disposal race.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Shutdown_completes_cleanly_with_active_subscriptions_and_no_disposal_race()
     {
@@ -167,6 +173,7 @@ public sealed class S7DriverCodeReviewFixTests
     }
 
     /// <summary>Verifies that dispose after subscribe does not throw ObjectDisposedException.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Dispose_after_subscribe_does_not_throw_ObjectDisposedException()
     {