fix: resolve DuplicateIdError by including search_term in drug-fragment badge IDs (Task 7.1)

Badge IDs changed from f"{directorate}|{frag}" to f"{directorate}|{search_term}|{frag}"
to handle fragments appearing under multiple indications within the same directorate.
Callback parsing updated to use rsplit("|", 1)[-1] for the 3-part key.

dash_app/components/drawer.py

@@ -63,7 +63,7 @@ def _make_directorate_card(directorate: str, indications: dict[str, list[str]])
                             children=[
                                 dmc.Badge(
                                     frag,
-                                    id={"type": "drug-fragment", "index": f"{directorate}|{frag}"},
+                                    id={"type": "drug-fragment", "index": f"{directorate}|{search_term}|{frag}"},
                                     variant="light",
                                     size="sm",
                                     className="drawer-drug-badge",