Add ClickHouse web datasource docs and update shared authentication guidance

[Copilot]

• Review the current ClickHouse English topic and the existing Japanese datasource/authentication docs structure
• Add the Japanese ClickHouse topic under the current Japanese web docs
• Update the Japanese authentication doc to include ClickHouse username/password support and the domain limitation
• Fix the English ClickHouse topic so its examples and custom-query precedence guidance stay consistent with the Japanese topic
• Validate the Japanese docs changes with the existing typecheck and build commands