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/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Browsing/BrowseSessionReaperTests.cs

@@ -14,6 +14,8 @@ public sealed class BrowseSessionReaperTests
     private static BrowseSessionReaper NewReaper(BrowseSessionRegistry registry) =>
         new(registry, NullLogger<BrowseSessionReaper>.Instance);
 
+    /// <summary>Verifies that ReapOnceAsync evicts a session that has been idle beyond the timeout.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ReapOnceAsync_evicts_idle_session()
     {
@@ -31,6 +33,8 @@ public sealed class BrowseSessionReaperTests
         session.Disposed.ShouldBeTrue();
     }
 
+    /// <summary>Verifies that ReapOnceAsync preserves a recently used session.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ReapOnceAsync_preserves_recent_session()
     {
@@ -45,6 +49,8 @@ public sealed class BrowseSessionReaperTests
         session.Disposed.ShouldBeFalse();
     }
 
+    /// <summary>Verifies that ReapOnceAsync handles a session already removed from the registry without throwing.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ReapOnceAsync_handles_already_removed_session()
     {
@@ -65,6 +71,8 @@ public sealed class BrowseSessionReaperTests
         session.Disposed.ShouldBeFalse();
     }
 
+    /// <summary>Verifies that ReapOnceAsync continues processing remaining sessions when one session's dispose throws.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ReapOnceAsync_continues_when_one_session_dispose_throws()
     {

tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Browsing/BrowseSessionRegistryTests.cs

@@ -9,6 +9,7 @@ namespace ZB.MOM.WW.OtOpcUa.AdminUI.Tests.Browsing;
 /// concurrent-registration behaviour.</summary>
 public sealed class BrowseSessionRegistryTests
 {
+    /// <summary>Verifies that a registered session can be retrieved by its token.</summary>
     [Fact]
     public void Register_then_TryGet_returns_session()
     {
@@ -22,6 +23,7 @@ public sealed class BrowseSessionRegistryTests
         got.ShouldBeSameAs((IBrowseSession)session);
     }
 
+    /// <summary>Verifies that looking up an unknown token returns false.</summary>
     [Fact]
     public void TryGet_unknown_returns_false()
     {
@@ -31,6 +33,7 @@ public sealed class BrowseSessionRegistryTests
         got.ShouldBeNull();
     }
 
+    /// <summary>Verifies that a removed session can no longer be retrieved.</summary>
     [Fact]
     public void TryRemove_then_TryGet_returns_false()
     {
@@ -43,6 +46,8 @@ public sealed class BrowseSessionRegistryTests
         registry.TryGet(session.Token, out _).ShouldBeFalse();
     }
 
+    /// <summary>Verifies that concurrent registrations from many tasks are all visible in the snapshot.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Concurrent_Register_from_many_tasks_all_visible_in_Snapshot()
     {

tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Browsing/BrowserSessionServiceTests.cs

@@ -15,6 +15,8 @@ public sealed class BrowserSessionServiceTests
         BrowseSessionRegistry registry, params IDriverBrowser[] browsers) =>
         new(browsers, registry, NullLogger<BrowserSessionService>.Instance);
 
+    /// <summary>Verifies that OpenAsync returns Ok=false with a message when the driver type is unknown.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task OpenAsync_unknown_driver_type_returns_Ok_false_with_message()
     {
@@ -29,6 +31,8 @@ public sealed class BrowserSessionServiceTests
         result.Message!.ShouldContain("Unknown");
     }
 
+    /// <summary>Verifies that OpenAsync returns a token and registers the session on the happy path.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task OpenAsync_happy_path_returns_token_and_registers()
     {
@@ -50,6 +54,8 @@ public sealed class BrowserSessionServiceTests
         registered.ShouldBeSameAs((IBrowseSession)session);
     }
 
+    /// <summary>Verifies that OpenAsync swallows driver exceptions and returns Ok=false.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task OpenAsync_swallows_driver_throws_returns_Ok_false()
     {
@@ -68,6 +74,8 @@ public sealed class BrowserSessionServiceTests
         result.Message!.ShouldContain("boom");
     }
 
+    /// <summary>Verifies that RootAsync throws BrowseSessionNotFoundException for an unknown token.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task RootAsync_unknown_token_throws_BrowseSessionNotFoundException()
     {
@@ -78,6 +86,8 @@ public sealed class BrowserSessionServiceTests
             () => service.RootAsync(Guid.NewGuid(), CancellationToken.None));
     }
 
+    /// <summary>Verifies that RootAsync invokes the session Root method and returns its result.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task RootAsync_invokes_session_Root()
     {
@@ -96,6 +106,8 @@ public sealed class BrowserSessionServiceTests
         actual.ShouldBe(expected);
     }
 
+    /// <summary>Verifies that RootAsync cancels the call when the per-call timeout elapses.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task RootAsync_enforces_PerCallTimeout()
     {
@@ -118,6 +130,8 @@ public sealed class BrowserSessionServiceTests
         sw.Elapsed.ShouldBeLessThan(TimeSpan.FromSeconds(35));
     }
 
+    /// <summary>Verifies that CloseAsync removes the session from the registry and disposes it.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task CloseAsync_removes_and_disposes_session()
     {

tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Browsing/FakeBrowseSession.cs

@@ -11,7 +11,7 @@ internal sealed class FakeBrowseSession : IBrowseSession
     /// <inheritdoc />
     public Guid Token { get; } = Guid.NewGuid();
 
-    /// <summary>Mutable so tests can rewind the timestamp into the reaper's eviction window.</summary>
+    /// <inheritdoc />
     public DateTime LastUsedUtc { get; set; } = DateTime.UtcNow;
 
     /// <summary>True once <see cref="DisposeAsync"/> has run to completion.</summary>
@@ -40,7 +40,8 @@ internal sealed class FakeBrowseSession : IBrowseSession
     public Task<IReadOnlyList<AttributeInfo>> AttributesAsync(string nodeId, CancellationToken ct)
         => AttributesHandler?.Invoke(nodeId, ct) ?? Task.FromResult<IReadOnlyList<AttributeInfo>>(Array.Empty<AttributeInfo>());
 
-    /// <inheritdoc />
+    /// <summary>Disposes the fake browse session asynchronously, recording completion or throwing if configured.</summary>
+    /// <returns>A completed value task.</returns>
     public ValueTask DisposeAsync()
     {
         if (ThrowOnDispose) throw new InvalidOperationException("dispose-failed");