fix(translate): normalize backend dialect detection with explicit mapping

- Replace fragile substring check (any(kw in backend for kw in ('clickhouse', 'ch')))
  with a proper _backend_normalize mapping + exact comparison.
  Fixes misdetection of Greenplum (postgresql) and other backends.
- Add 'clickhousedb' to CLICKHOUSE_DIALECTS so SQL generator uses
  backtick quoting and correct INSERT strategy for ClickHouse.
- Normalize _extract_dialect to map 'clickhousedb' -> 'clickhouse'
  and 'greenplum' -> 'postgresql'.

backend/src/plugins/translate/service_target_schema.py

@@ -241,8 +241,31 @@ def validate_target_table_schema(
             safe_schema = (req.target_schema or "public").replace("'", "''")
             safe_table = req.target_table.replace("'", "''")
 
+            # Нормализуем backend через маппинг (как в get_dialect_from_database)
+            # чтобы правильно обработать "clickhousedb" → "clickhouse",
+            # "greenplum" → "postgresql" и другие варианты
+            _backend_normalize = {
+                "clickhouse": "clickhouse",
+                "clickhousedb": "clickhouse",
+                "postgresql": "postgresql",
+                "greenplum": "postgresql",
+                "mysql": "mysql",
+                "mssql": "mssql",
+                "sqlite": "sqlite",
+                "oracle": "oracle",
+                "snowflake": "snowflake",
+                "bigquery": "bigquery",
+                "redshift": "redshift",
+                "presto": "presto",
+                "trino": "trino",
+                "druid": "druid",
+                "hive": "hive",
+                "spark": "spark",
+                "databricks": "databricks",
+            }
+            normalized_backend = _backend_normalize.get(backend.lower().strip(), backend.lower().strip())
             # ClickHouse использует system.columns, всё остальное — information_schema.columns
-            is_clickhouse = any(kw in backend.lower() for kw in ("clickhouse", "ch"))
+            is_clickhouse = normalized_backend == "clickhouse"
             if is_clickhouse:
                 sql = (
                     f"SELECT name, type, default_expression AS data_default "

backend/src/plugins/translate/service_utils.py

@@ -7,15 +7,27 @@ from ...schemas.translate import TranslateJobResponse
 
 
 # #region _extract_dialect [TYPE Function]
-# @BRIEF Extract database dialect from Superset backend URI.
+# @BRIEF Extract database dialect from Superset backend URI or engine name.
 def _extract_dialect(backend: str) -> str:
-    """Extract dialect name from a Superset database backend URI."""
+    """Extract dialect name from a Superset database backend URI or engine name.
+
+    Handles both URI formats (e.g. 'postgresql://...', 'clickhousedb://...')
+    and plain engine names (e.g. 'postgresql', 'clickhousedb') returned by Superset.
+    Normalises known variants like 'clickhousedb' → 'clickhouse'.
+    """
     if not backend:
         return "unknown"
     try:
+        # Extract scheme from URI or use plain name
         scheme = backend.split("://")[0]
         dialect = scheme.split("+")[0]
-        return dialect.lower()
+        raw = dialect.lower()
+        # Normalise known Superset backend variants
+        dialect_map = {
+            "clickhousedb": "clickhouse",
+            "greenplum": "postgresql",
+        }
+        return dialect_map.get(raw, raw)
     except Exception:
         return "unknown"
 # #endregion _extract_dialect

backend/src/plugins/translate/sql_generator.py

@@ -18,7 +18,7 @@ from ...core.logger import belief_scope, logger
 # PostgreSQL/Greenplum dialects that support ON CONFLICT
 POSTGRESQL_DIALECTS = {"postgresql", "redshift", "greenplum"}
 # Dialects that use backtick or no quoting
-CLICKHOUSE_DIALECTS = {"clickhouse"}
+CLICKHOUSE_DIALECTS = {"clickhouse", "clickhousedb"}
 
 
 # #region _normalize_timestamp_value [C:2] [TYPE Function] [SEMANTICS translate,sql,timestamp]