fix(): Convert boundary completeness check into warning when GAI is used

[benflexcompute]

Note

Updates boundary completeness validation to be less strict under Geometry AI.

• Adds use_geometry_AI to _validate_boundary_completeness and passes param_info.use_geometry_AI, downgrading missing-BC errors to warnings when enabled
• Adjusts tests/simulation/params/test_automated_farfield.py to capture warnings from validate_model and assert warning messages instead of errors for missing BCs
• Adds tests in test_validators_params.py to explicitly verify missing BCs are warnings with Geometry AI and errors without it
• Extends farfield/legacy-asset tests to cover warning behavior when private_attributes are missing and when transformations/mirroring are present

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