diff --git a/site/app.py b/site/app.py
index 31ab8cb..56808e4 100644
--- a/site/app.py
+++ b/site/app.py
@@ -134,56 +134,74 @@ class ContractsApp:
 
     def _upload_json(self):
         """Принять файл как base64. Сохранить строкой (без декодирования — быстро)."""
-        data = request.get_json(silent=True)
-        _log("upload_entry", f"data={'yes' if data else 'no'}")
-        if not data:
-            return jsonify({"error": "Нет JSON"}), 400
-
-        filename = data.get("filename", "")
-        b64 = data.get("data", "")
-        if not filename or not b64:
-            return jsonify({"error": "Нет filename или data"}), 400
-
-        mime = mimeutil.guess_mime(filename) or "application/octet-stream"
-        cid = data.get("cid")
-
-        conn, err = db.connect()
-        if err:
-            return jsonify({"error": f"БД: {err}"}), 500
+        _log("upload_entry", "start")
         try:
-            cur = conn.cursor()
-            if cid:
-                contract_id = cid
-            else:
-                cur.execute(
-                    "INSERT INTO contracts (number, client) VALUES (%s, %s) RETURNING id",
-                    ("б/н " + __import__("datetime").datetime.now().strftime("%Y%m%d-%H%M"), ""),
-                )
-                contract_id = cur.fetchone()[0]
+            data = request.get_json(silent=True)
+            _log("upload_json_parsed", f"data={'yes' if data else 'no'} len={len(request.data) if request.data else 0}")
+            if not data:
+                return jsonify({"error": "Нет JSON"}), 400
+
+            filename = data.get("filename", "")
+            b64 = data.get("data", "")
+            _log("upload_fields", f"file={filename} b64_len={len(b64) if b64 else 0} cid={data.get('cid')}")
+            if not filename or not b64:
+                return jsonify({"error": "Нет filename или data"}), 400
+
+            mime = mimeutil.guess_mime(filename) or "application/octet-stream"
+            cid = data.get("cid")
+
+            conn, err = db.connect()
+            _log("upload_connect", f"err={err}")
+            if err:
+                return jsonify({"error": f"БД: {err}"}), 500
+            try:
+                cur = conn.cursor()
+                if cid:
+                    contract_id = cid
+                    _log("upload_contract", f"reuse cid={cid}")
+                else:
+                    cur.execute(
+                        "INSERT INTO contracts (number, client) VALUES (%s, %s) RETURNING id",
+                        ("б/н " + __import__("datetime").datetime.now().strftime("%Y%m%d-%H%M"), ""),
+                    )
+                    contract_id = cur.fetchone()[0]
+                    _log("upload_contract", f"new cid={contract_id}")
 
-            # Сохранить base64 как текст (быстро)
-            cur.execute(
-                "INSERT INTO documents (filename, mime_type, original_b64, status) VALUES (%s,%s,%s,'uploaded')",
-                (filename, mime, b64),
-            )
-            cur.execute("SELECT id FROM documents WHERE filename=%s AND status='uploaded' ORDER BY created_at DESC LIMIT 1", (filename,))
-            row = cur.fetchone()
-            doc_id = row[0] if row else None
-            if doc_id:
                 cur.execute(
-                    "INSERT INTO supplements (contract_id, document_id, type) VALUES (%s,%s,'initial')",
-                    (str(contract_id), str(doc_id)),
+                    "INSERT INTO documents (filename, mime_type, original_b64, status) VALUES (%s,%s,%s,'uploaded')",
+                    (filename, mime, b64),
                 )
-            conn.commit()
-            cur.close()
+                _log("upload_doc_insert", "ok")
+
+                cur.execute("SELECT id FROM documents WHERE filename=%s AND status='uploaded' ORDER BY created_at DESC LIMIT 1", (filename,))
+                row = cur.fetchone()
+                doc_id = row[0] if row else None
+                _log("upload_doc_select", f"doc_id={doc_id}")
+
+                if doc_id:
+                    cur.execute(
+                        "INSERT INTO supplements (contract_id, document_id, type) VALUES (%s,%s,'initial')",
+                        (str(contract_id), str(doc_id)),
+                    )
+                    _log("upload_suppl", "ok")
+
+                conn.commit()
+                _log("upload_commit", "ok")
+                cur.close()
+            except Exception as e:
+                _log("upload_error", str(e))
+                try: conn.rollback()
+                except: pass
+                raise e
+            finally:
+                db.put_conn(conn)
+                _log("upload_putconn", "ok")
+
+            _log("upload_done", f"cid={contract_id} doc={doc_id}")
+            return jsonify({"contract_id": str(contract_id), "doc_id": str(doc_id) if doc_id else None})
         except Exception as e:
-            try: conn.rollback()
-            except: pass
-            raise e
-        finally:
-            db.put_conn(conn)
-
-        return jsonify({"contract_id": str(contract_id), "doc_id": str(doc_id) if doc_id else None})
+            _log("upload_outer_error", str(e))
+            return jsonify({"error": f"Крах: {e}"}), 500
 
     # ── Чанковая загрузка ──────────────────────────────────────