fix: add type narrowing for LineByLineEvaluationDetails in tests

Added isinstance() checks to help mypy understand that result.details
is specifically a LineByLineEvaluationDetails object, not just the
generic str | BaseModel | None type.

This fixes mypy errors when accessing total_lines_actual and
total_lines_expected attributes.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: AAgnihotry

packages/uipath/tests/evaluators/test_line_by_line_utils.py

@@ -9,7 +9,10 @@
     split_into_lines,
     wrap_line_in_structure,
 )
-from uipath.eval.evaluators.output_evaluator import LineEvaluationDetail
+from uipath.eval.evaluators.output_evaluator import (
+    LineByLineEvaluationDetails,
+    LineEvaluationDetail,
+)
 from uipath.eval.models.models import AgentExecution, NumericEvaluationResult
 
 
@@ -285,6 +288,7 @@ def test_build_result_with_all_matches(self):
         assert isinstance(result, NumericEvaluationResult)
         assert result.score == 1.0
         assert hasattr(result, "_line_by_line_results")
+        assert isinstance(result.details, LineByLineEvaluationDetails)
         assert result.details.total_lines_actual == 2
         assert result.details.total_lines_expected == 2
 
@@ -346,6 +350,7 @@ def test_build_result_with_unequal_line_counts(self):
         )
 
         assert isinstance(result, NumericEvaluationResult)
+        assert isinstance(result.details, LineByLineEvaluationDetails)
         assert result.details.total_lines_actual == 1
         assert result.details.total_lines_expected == 2
         assert result.score == 0.5  # 1/2