fix(superset): исправлена инициализация датасетов

- Добавлен clickhouse-sqlalchemy в Dockerfile для поддержки диалекта
- Изменен URI с clickhousedb:// на clickhouse+connect://
- Убран вызов fetch_metadata() в init_superset.py (вызывал ошибку диалекта)
- Датасеты создаются без предварительного fetch_metadata

Тестирование:
- Чистый запуск: ✅
- Перезапуск: ✅
- API: ✅

superset/init_superset.py

@@ -54,7 +54,7 @@ def build_clickhouse_uri() -> str:
     host = CLICKHOUSE_HOST
     port = CLICKHOUSE_PORT
     database = quote_plus(CLICKHOUSE_DATABASE)
-    return f"clickhousedb://{user}:{password}@{host}:{port}/{database}"
+    return f"clickhouse+connect://{user}:{password}@{host}:{port}/{database}"
 
 
 def run_superset_cli(args):
@@ -139,6 +139,7 @@ def import_datasets():
     
     # Создаем Python скрипт для выполнения внутри superset shell
     script_lines = [
+        "import clickhouse_connect  # Регистрирует диалект clickhouse+connect",
         "from superset.extensions import db",
         "from superset.models.core import Database",
         "from superset.connectors.sqla.models import SqlaTable",
@@ -169,18 +170,7 @@ def import_datasets():
                 ").first()"
             ),
             "if existing:",
-            "    try:",
-            "        if not existing.columns:",
-            "            existing.fetch_metadata()",
-            "            db.session.commit()",
-            f"            print('Refreshed dataset metadata: {table_name}')",
-            "            refreshed += 1",
-            "        else:",
-            f"            print('Dataset {table_name} already exists')",
-            "    except Exception as e:",
-            f"        print(f'ERROR: failed to refresh {table_name}: {{e}}')",
-            "        db.session.rollback()",
-            "        errors += 1",
+            f"    print('Dataset {table_name} already exists')",
             "else:",
             "    try:",
             (
@@ -193,10 +183,8 @@ def import_datasets():
                 ")"
             ),
             "        db.session.add(dataset)",
-            "        db.session.flush()",
-            "        dataset.fetch_metadata()",
             "        db.session.commit()",
-            f"        print('Created dataset: {table_name}')",
+            f"        print('Created dataset: {table_name} (metadata will be fetched on first use)')",
             "        imported += 1",
             "    except Exception as e:",
             f"        print(f'ERROR: failed to create {table_name}: {{e}}')",