Fix ruff finding

Author: djm81

src/specfact_cli/analyzers/ambiguity_scanner.py

@@ -10,7 +10,7 @@
 import ast
 import re
 from dataclasses import dataclass
-from enum import Enum
+from enum import StrEnum
 from pathlib import Path
 
 from beartype import beartype
@@ -19,15 +19,15 @@
 from specfact_cli.models.plan import PlanBundle
 
 
-class AmbiguityStatus(str, Enum):
+class AmbiguityStatus(StrEnum):
     """Ambiguity status levels."""
 
     CLEAR = "Clear"
     PARTIAL = "Partial"
     MISSING = "Missing"
 
 
-class TaxonomyCategory(str, Enum):
+class TaxonomyCategory(StrEnum):
     """Taxonomy categories for ambiguity detection."""
 
     FUNCTIONAL_SCOPE = "Functional Scope & Behavior"