Fix case study file browser state when switching conversations

streamlit-client/app.py

@@ -578,12 +578,14 @@ if st.session_state.view_mode == "case_study":
     case_dir = selected_path.parent
     ws_dir = case_dir / "workspace"
     browse_path = ws_dir if ws_dir.exists() else case_dir
+    # Use a case-specific key so switching case study resets browser state correctly
+    fb_key = f"case_study_file_browser_{case_dir.name}"
     with st.expander("📂 Workspace Files (Agent Code)", expanded=False):
         st.caption(f"Browsing: `{browse_path.resolve()}`")
         if st_file_browser is not None:
             st_file_browser(
                 str(browse_path.resolve()),
-                key="case_study_file_browser",
+                key=fb_key,
                 show_choose_file=True,
                 show_download_file=True,
                 show_delete_file=False,