Parameter required status is lost after wire round-trip #3854

Describe the bug

Parameter serializes its computed required flag, but _reconstruct_param_type_from_wire does not use it to restore REQUIRED_VALUE. A required declaration therefore deserializes as optional (default=None, required=False). Clients that round-trip a registry catalog can stop marking or validating the field as required, although backend construction still rejects a missing input.

Steps/Code to Reproduce

from pyrit.common import REQUIRED_VALUE
from pyrit.models.parameter import Parameter

original = Parameter(name="count", description="Required count", param_type=int, default=REQUIRED_VALUE)
restored = Parameter.model_validate_json(original.model_dump_json())
print(original.required, restored.required, restored.default)

Expected Results

The restored declaration remains required and has the same missing-input validation semantics as the original.

Actual Results

The wire JSON contains "required":true, but the restored model reports True False None for original required, restored required, and restored default.

Screenshots

N/A. This is a deterministic model serialization reproduction.

Versions

Python 3.12.3; PyRIT checkout revision 01ce6ca66a315770b36c7dca1f320668c0d92d7c. tests/unit/models/test_parameter.py (228 tests) and registry resolution tests (93 tests) passed; no backend HTTP workflow was run.