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/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()
     {