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Description

This PR resolves #1373 and #1369 , where a subdomain entered before selecting a base domain was not saved when creating or editing a resource.

Changes introduced:

• Users can safely type a subdomain before choosing a base domain without losing input.
• Subdomain change and base domain selection now both trigger validation → ensuring state stays in sync regardless of order of operations.
• Improved subdomain validation to ensure consistency across inputs.
• The subdomain is sanitized (invalid characters removed).
• If compatible, it is preserved and combined with the base domain.

How to test?