fix(superset): align bootstrap with clickhousedb uri

- Why:
  - Superset bootstrap used outdated ClickHouse URI format and did not fail fast on init errors.
  - docs and exported dashboard metadata diverged from runtime connection settings.
- What:
  - build ClickHouse URI from env vars and use clickhousedb:// in init script.
  - refresh dataset metadata on existing datasets and surface import errors.
  - run create_dashboard during superset-init startup and align docs/exported URI references.
  - ignore node_modules in git.
- Check:
  - python3 -m py_compile superset/init_superset.py
  - manual dashboard smoke check in UI (charts render)

docs/SUPERSET_DASHBOARD.md

@@ -93,7 +93,7 @@ make superset-dashboard
 # Основные
 make up          # Запуск всех сервисов
 make down        # Остановка сервисов
-make down-v      # Остановка с удалением volumes
+make clean      # Остановка с удалением volumes
 make logs service=superset  # Логи сервиса
 
 # ETL
@@ -120,7 +120,7 @@ make superset-restart   # Перезапуск сервиса
 3. Выберите **ClickHouse**
 4. Введите SQLAlchemy URI:
    ```
-   clickhouse+native://default@clickhouse:9000/default
+   clickhousedb://default:123456@clickhouse:8123/default
    ```
 5. Установите:
    - **Expose in SQL Lab:** ✅