[Feature Request]: Support UNIQUE / PRIMARY KEY and Upsert

[Mila-1001]

Is there an existing issue for the same feature request?

• [x] I have checked the existing issues.

Is your feature request related to a problem?

Describe the feature you'd like

Infinity currently does not support user-defined unique constraints or primary keys. This makes it hard to guarantee uniqueness of business keys (e.g., resume_id) and to perform upserts.

Describe implementation you've considered

No response

Documentation, adoption, use case

Additional information

No response