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  - Superset bootstrap used outdated ClickHouse URI format and did not fail fast on init errors.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/ARCHITECTURE.md

@@ -602,7 +602,7 @@ INSERT INTO dm.daily_traffic SELECT * FROM dm.v_daily_traffic;
 - URL: `clickhouse://default:123456@clickhouse:9000/default` (native TCP для Airflow plugin)
 - Provider/интеграция: `airflow-clickhouse-plugin` (в `airflow/requirements.txt`), задачи выполняются через `ClickHouseOperator`.
 - Дополнительно: `kafka-python==2.0.6` для работы с Kafka из DAG.
-- Примечание: Superset подключается к ClickHouse по HTTP (обычно `clickhouse+connect://...:8123/...`).
+- Примечание: Superset подключается к ClickHouse по HTTP (обычно `clickhousedb://...:8123/...`).
 
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