Fix recorder drag collapse, focus events, ts/raw_coord (#6)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/Recordingtest.Recorder/Scenario.cs

@@ -18,11 +18,19 @@ public sealed class ScenarioSut
 
 public sealed class ScenarioStep
 {
-    /// <summary>click | type | drag | hotkey | wait</summary>
+    /// <summary>click | type | drag | hotkey | wait | focus</summary>
     public string Kind { get; set; } = "click";
     public ScenarioTarget? Target { get; set; }
     public string? Value { get; set; }
     public string? WaitFor { get; set; }
+    /// <summary>ms since recording start (or epoch ms from RawEvent).</summary>
+    public long Ts { get; set; }
+    /// <summary>Raw screen coordinate [x, y] when applicable.</summary>
+    public int[]? RawCoord { get; set; }
+    /// <summary>For drag steps: end offset within target element.</summary>
+    public double[]? EndOffset { get; set; }
+    /// <summary>For drag steps: end raw coordinate [x, y].</summary>
+    public int[]? EndRawCoord { get; set; }
 }
 
 public sealed class ScenarioTarget