fix(clickhouse): register table comments via command instead of inline CTAS

ClickhouseEngineAdapter set COMMENT_CREATION_VIEW to COMMENT_COMMAND_ONLY but
never set COMMENT_CREATION_TABLE, so it silently inherited the EngineAdapter
default of IN_SCHEMA_DEF_CTAS. That default asserts the engine can embed
COMMENT '...' inside a CREATE TABLE ... AS SELECT, which ClickHouse Cloud
rejects with a syntax error (code 62, SYNTAX_ERROR).

Setting COMMENT_CREATION_TABLE to COMMENT_COMMAND_ONLY keeps the comment out
of the CTAS entirely and routes both the table description and the column
descriptions through the post-create ALTER TABLE ... MODIFY COMMENT and
ALTER TABLE ... COMMENT COLUMN paths, which the adapter already implements
and which views already rely on.

Fixes #5969

Signed-off-by: cookieark <aishwary.kantode@gmail.com>

Author: cookieark

sqlmesh/core/engine_adapter/clickhouse.py

@@ -13,6 +13,7 @@
     DataObjectType,
     EngineRunMode,
     SourceQuery,
+    CommentCreationTable,
     CommentCreationView,
     InsertOverwriteStrategy,
 )
@@ -36,6 +37,7 @@ class ClickhouseEngineAdapter(EngineAdapterWithIndexSupport, LogicalMergeMixin):
     SUPPORTS_TRANSACTIONS = False
     SUPPORTS_VIEW_SCHEMA = False
     SUPPORTS_REPLACE_TABLE = False
+    COMMENT_CREATION_TABLE = CommentCreationTable.COMMENT_COMMAND_ONLY
     COMMENT_CREATION_VIEW = CommentCreationView.COMMENT_COMMAND_ONLY
 
     SCHEMA_DIFFER_KWARGS = {}