Analyze sr_api_field schema for domain handling

[huzz5991]

Add bizFieldDomainId to ApiField to enable referencing domain-specific fields in API definitions.

Previously, sr_api_field could only reference base fields (sr_biz_field). This change introduces biz_field_domain_id to allow API fields to link to sr_biz_field_domain entries, providing a way to use fields with specific domain contexts. This design maintains backward compatibility with existing base field references, with biz_field_domain_id taking precedence if present.

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[cursor]

Cursor Agent can help with this pull request. Just @cursor in comments and I'll start working on changes in this branch.
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