Fix XTerm.NET build warnings

src/XTerm.NET.Tests/OscSequenceTests.cs

@@ -127,12 +127,18 @@ public void OscHyperlink_StartLink_SetsHyperlink()
     {
         // Arrange
         var terminal = CreateTerminal();
+        string? changedUrl = null;
+        var isCleared = true;
+        terminal.HyperlinkChanged += (sender, e) => changedUrl = e.Url;
+        terminal.HyperlinkChanged += (sender, e) => isCleared = e.IsCleared;
 
         // Act
         terminal.Write("\x1B]8;;http://example.com\x07");
 
         // Assert
         Assert.Equal("http://example.com", terminal.CurrentHyperlink);
+        Assert.Equal("http://example.com", changedUrl);
+        Assert.False(isCleared);
     }
 
     [Fact]
@@ -141,12 +147,24 @@ public void OscHyperlink_EndLink_ClearsHyperlink()
         // Arrange
         var terminal = CreateTerminal();
         terminal.Write("\x1B]8;;http://example.com\x07");
+        var eventCount = 0;
+        string changedUrl = "not cleared";
+        var isCleared = false;
+        terminal.HyperlinkChanged += (sender, e) =>
+        {
+            eventCount++;
+            changedUrl = e.Url;
+            isCleared = e.IsCleared;
+        };
 
         // Act
         terminal.Write("\x1B]8;;\x07");
 
         // Assert
         Assert.Null(terminal.CurrentHyperlink);
+        Assert.Equal(1, eventCount);
+        Assert.Equal(string.Empty, changedUrl);
+        Assert.True(isCleared);
     }
 
     [Fact]

src/XTerm.NET/Events/TerminalEvents.cs

@@ -133,15 +133,29 @@ public DirectoryChangeEventArgs(string directory)
     }
 
     /// <summary>
-    /// Hyperlink event - fired when a hyperlink is encountered.
+    /// Hyperlink event - fired when a hyperlink is encountered or cleared.
     /// </summary>
     public class HyperlinkEventArgs : EventArgs
     {
+        /// <summary>
+        /// Hyperlink URL. Empty when <see cref="IsCleared"/> is true.
+        /// </summary>
         public string Url { get; }
+
+        /// <summary>
+        /// True when the active hyperlink was cleared.
+        /// </summary>
+        public bool IsCleared { get; }
 
         public HyperlinkEventArgs(string url)
+            : this(url, false)
+        {
+        }
+
+        internal HyperlinkEventArgs(string url, bool isCleared)
         {
             Url = url;
+            IsCleared = isCleared;
         }
     }
 
@@ -267,4 +281,3 @@ public CursorStyleChangedEventArgs(CursorStyle style, bool blink)
         }
     }
 }
-

src/XTerm.NET/InputHandler.cs

@@ -704,6 +704,7 @@ private void HandleHyperlink(string data)
                 // End hyperlink
                 _terminal.CurrentHyperlink = null;
                 _terminal.HyperlinkId = null;
+                _terminal.RaiseHyperlinkChanged(null);
             }
             else
             {
@@ -722,6 +723,8 @@ private void HandleHyperlink(string data)
                         }
                     }
                 }
+
+                _terminal.RaiseHyperlinkChanged(uri);
             }
         }
     }

src/XTerm.NET/Parser/EscapeSequenceParser.cs

@@ -44,9 +44,12 @@ public class EscapeSequenceParser
     public event EventHandler<OscEventArgs>? Osc;
 
     /// <summary>
-    /// Fired when DCS sequences are parsed.
+    /// DCS parsing is not implemented yet. This event is retained for source compatibility.
     /// </summary>
+#pragma warning disable CS0067
+    [Obsolete("DCS parsing is not implemented yet; this event is retained for source compatibility.")]
     public event EventHandler<DcsEventArgs>? Dcs;
+#pragma warning restore CS0067
 
     public EscapeSequenceParser()
     {

src/XTerm.NET/Terminal.cs

@@ -476,6 +476,9 @@ internal void RaiseTitleChanged(string title) =>
 
     internal void RaiseDirectoryChanged(string directory) => 
         DirectoryChanged?.Invoke(this, new TerminalEvents.DirectoryChangeEventArgs(directory));
+
+    internal void RaiseHyperlinkChanged(string? url) =>
+        HyperlinkChanged?.Invoke(this, new TerminalEvents.HyperlinkEventArgs(url ?? string.Empty, url == null));
 
     internal void RaiseWindowMoved(int x, int y) => 
         WindowMoved?.Invoke(this, new TerminalEvents.WindowMovedEventArgs(x, y));