feat: edit and delete pairs in GenerateIt

- Backend: PATCH /api/directus/db-pairs/<id> updates level, statement, question
  (creates question if new, removes if cleared)
- Backend: DELETE /api/directus/db-pairs/<id> removes pair + all junctions,
  questions and statements
- Frontend: inline edit form per pair (level slider, statement, question)
- Frontend: delete button per pair with confirm dialog
- api.ts: updateDbPair, deleteDbPair

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app.py

@@ -1877,6 +1877,88 @@ def directus_db_object_pairs(obj_id):
         return jsonify({"ok": True, "pair_id": pair_id, "statement_id": stmt_id, "question_id": q_id})
 
 
+@app.route("/api/directus/db-pairs/<pair_id>", methods=["PATCH", "DELETE"])
+def directus_db_pair(pair_id):
+    """PATCH: level + question/statement inline aktualisieren.
+    DELETE: Pair + alle verknüpften Junctions + Question + Statement entfernen."""
+    token = request.headers.get("Authorization", "")
+
+    if request.method == "PATCH":
+        body = request.get_json(force=True, silent=True) or {}
+
+        # Pair-Level updaten
+        if "level" in body:
+            _directus("PATCH", f"/items/db_pairs/{pair_id}", token, {"level": body["level"]})
+
+        # Statement updaten (nur erstes verknüpftes)
+        if "statement_de" in body:
+            s_junc, _ = _directus("GET",
+                f"/items/db_pairs_db_statement?filter[db_pairs_id][_eq]={pair_id}&fields=db_statement_id&limit=1", token)
+            for e in (s_junc.get("data") or []):
+                sid = e.get("db_statement_id")
+                if sid:
+                    _directus("PATCH", f"/items/db_statement/{sid}", token,
+                              {"statement_de": body["statement_de"], "level": body.get("level", 50)})
+
+        # Question updaten/anlegen
+        if "question_de" in body:
+            question_de = (body["question_de"] or "").strip()
+            q_junc, _ = _directus("GET",
+                f"/items/db_pairs_db_question?filter[db_pairs_id][_eq]={pair_id}&fields=db_question_id&limit=1", token)
+            existing_q = (q_junc.get("data") or [])
+            if existing_q:
+                qid = existing_q[0].get("db_question_id")
+                if question_de:
+                    _directus("PATCH", f"/items/db_question/{qid}", token,
+                              {"question_de": question_de, "level": body.get("level", 50)})
+                else:
+                    # Frage gelöscht → Junction + Item entfernen
+                    _directus("DELETE", f"/items/db_pairs_db_question", token,
+                              [e["id"] for e in existing_q if e.get("id")])
+                    _directus("DELETE", f"/items/db_question/{qid}", token)
+            elif question_de:
+                # Neue Frage anlegen und verknüpfen
+                q_resp, s = _directus("POST", "/items/db_question", token,
+                                      {"status": "draft", "question_de": question_de,
+                                       "level": body.get("level", 50)})
+                if s in (200, 201):
+                    qid = q_resp["data"]["id"]
+                    _directus("POST", "/items/db_pairs_db_question", token,
+                              {"db_pairs_id": pair_id, "db_question_id": qid})
+
+        return jsonify({"ok": True})
+
+    else:  # DELETE
+        # Junction zu Objekten entfernen
+        obj_junc, _ = _directus("GET",
+            f"/items/db_objects_db_pairs?filter[db_pairs_id][_eq]={pair_id}&fields=id&limit=100", token)
+        obj_junc_ids = [e["id"] for e in (obj_junc.get("data") or []) if e.get("id")]
+        if obj_junc_ids:
+            _directus("DELETE", "/items/db_objects_db_pairs", token, obj_junc_ids)
+
+        # Questions löschen
+        q_junc, _ = _directus("GET",
+            f"/items/db_pairs_db_question?filter[db_pairs_id][_eq]={pair_id}&fields=id,db_question_id&limit=100", token)
+        for e in (q_junc.get("data") or []):
+            if e.get("id"):
+                _directus("DELETE", f"/items/db_pairs_db_question/{e['id']}", token)
+            if e.get("db_question_id"):
+                _directus("DELETE", f"/items/db_question/{e['db_question_id']}", token)
+
+        # Statements löschen
+        s_junc, _ = _directus("GET",
+            f"/items/db_pairs_db_statement?filter[db_pairs_id][_eq]={pair_id}&fields=id,db_statement_id&limit=100", token)
+        for e in (s_junc.get("data") or []):
+            if e.get("id"):
+                _directus("DELETE", f"/items/db_pairs_db_statement/{e['id']}", token)
+            if e.get("db_statement_id"):
+                _directus("DELETE", f"/items/db_statement/{e['db_statement_id']}", token)
+
+        # Pair selbst löschen
+        _, s = _directus("DELETE", f"/items/db_pairs/{pair_id}", token)
+        return jsonify({"ok": s in (200, 204)})
+
+
 if __name__ == "__main__":
     app.run(host="0.0.0.0", port=8000, debug=True)