fix(chat): route inventory item-link addIfNotPresent into InputBar

The AddonChatLog.OnRefresh hook is registered and fires correctly
when the user picks "Link item" from the inventory right-click menu
in-game. The detour extracts addIfNotPresent="<item>" from the
AtkValue array — verified empirically via a temporary _logger.LogDebug
diagnostic build (eventId=31 valueUInt=C addIfNotPresent=<item>).

Pre-fix the extracted value was discarded with `_ = addIfNotPresent;`
and a comment "Chat-window Activated integration is offline until the
new chat layer surfaces an Activated entry point." The Activated entry
point on the new v1.7.0 component layer has existed since that cycle
(InputBar.AppendPending + InputBar.Activate, same pattern as
PayloadHandler.DrawStatusPopup:546-549), but the rewiring was forgotten
when ChatLogWindow.Activated() was removed.

Route addIfNotPresent through InputBar.AppendPending with a
v1.5.6-equivalent !PendingMessage.Contains() guard to prevent
double-insertion on repeated OnRefresh events. Activate = true marks
the input bar for ImGui.SetKeyboardFocusHere on the next draw, so the
user can immediately keep typing after the link is inserted.

Verified in-game: right-click "Link item" on multiple inventory items
inserts <item> into the HellionChat input bar, repeated link insertion
does not produce <item><item>, MainWindow gains keyboard focus.

HellionChat/GameFunctions/Chat.cs

@@ -248,9 +248,13 @@ internal sealed unsafe class Chat : IDisposable
                 addIfNotPresent = add;
         }
 
-        // Chat-window Activated integration is offline until the new chat
-        // layer surfaces an Activated entry point.
-        _ = addIfNotPresent;
+        // Route the addIfNotPresent token into the InputBar so inventory
+        // right-click "Link item" reaches our input field instead of being lost.
+        if (addIfNotPresent != null && !Plugin.InputBar.PendingMessage.Contains(addIfNotPresent))
+        {
+            Plugin.InputBar.AppendPending(addIfNotPresent);
+            Plugin.InputBar.Activate = true;
+        }
 
         return 1; // Prevent vanilla chat log from gaining focus
     }