feat(debugger): reactivate PayloadHandler counters (R3)

K reactivates the debugger's PayloadHandler counter readout
(HandleTooltips / HoveredItem / HoverCounter / LastHoverCounter —
populated in E1's PayloadHandler skeleton). PayloadHandler injected
via DI-extended ctor; class flipped to internal sealed to match
PayloadHandler's internal visibility and avoid CS0051. Plugin.cs
property updated public → internal accordingly (same pattern as I/J).

Last Phase-3 window sub-task before A2 (Lender + handler.Draw fix),
J2 (InputBar slash-callback), Polish-Sweep, and Smoke-Gate.

HellionChat/Ui/Debugger.cs

@@ -11,16 +11,16 @@ namespace HellionChat.Ui;
 
 // Dev tool. Reduced to the parts that survive without the legacy chat
 // window: current-tab channel state and the vanilla chat channel label.
-// The chat-window cursor and payload-handler counters come back once the
-// new chat layer surfaces equivalent state.
-public class DebuggerWindow : Window, IDisposable
+internal sealed class DebuggerWindow : Window, IDisposable
 {
     private readonly Plugin Plugin;
+    private readonly PayloadHandler _payloadHandler;
 
-    public DebuggerWindow(Plugin plugin)
+    public DebuggerWindow(Plugin plugin, PayloadHandler payloadHandler)
         : base("Debugger###chat2-debugger")
     {
         Plugin = plugin;
+        _payloadHandler = payloadHandler;
 
         SizeConstraints = new WindowSizeConstraints
         {
@@ -41,7 +41,10 @@ public class DebuggerWindow : Window, IDisposable
             ImGui.SetClipboardText(agent.ToString("X"));
 
         ImGuiHelpers.ScaledDummy(5.0f);
-        ImGui.TextDisabled("Payload handler counters: offline during the chat rebuild.");
+        ImGui.TextUnformatted($"Handle Tooltips: {_payloadHandler.HandleTooltips}");
+        ImGui.TextUnformatted($"Hovered Item: {_payloadHandler.HoveredItem}");
+        ImGui.TextUnformatted($"Hover Counter: {_payloadHandler.HoverCounter}");
+        ImGui.TextUnformatted($"Last Hover Counter: {_payloadHandler.LastHoverCounter}");
 
         ImGuiHelpers.ScaledDummy(5.0f);
         ImGui.TextColored(ImGuiColors.DalamudOrange, "Current Tab");