feat(gui): Add branch discussion action to history entries

src/gui_2.py

@@ -2479,6 +2479,8 @@ def hello():
        imgui.pop_id()
        break # Break from inner loop, clipper will re-step
       imgui.same_line()
+      if imgui.button("Branch"):
+       self._branch_discussion(i)      imgui.same_line()
       preview = entry["content"].replace("\\n", " ")[:60]
       if len(entry["content"]) > 60: preview += "..."
       if not preview.strip() and entry.get("thinking_segments"):