fix: enable word wrap in chat log

RichLog defaults wrap=False, causing long messages to extend
beyond the visible area instead of wrapping at the widget edge.

src/tuimble/app.py

@@ -187,7 +187,7 @@ class ChatLog(RichLog):
     """Message log."""
 
     def __init__(self, **kwargs) -> None:
-        super().__init__(markup=True, **kwargs)
+        super().__init__(markup=True, wrap=True, **kwargs)
 
 
 # -- main app ----------------------------------------------------------------