Add semantic versioning validator to _Versioned mixin

requirements.txt

@@ -14,3 +14,4 @@ scikit-learn==1.6.1
 jsonschema==4.23.0
 networkx==3.4.2
 pydantic==2.10.6
+semver==3.0.2

src/ssvc/_mixins.py

@@ -17,7 +17,8 @@
 
 from typing import Optional
 
-from pydantic import BaseModel, ConfigDict
+from pydantic import BaseModel, ConfigDict, field_validator
+from semver import Version
 
 from . import _schemaVersion
 
@@ -30,6 +31,23 @@ class _Versioned(BaseModel):
     version: str = "0.0.0"
     schemaVersion: str = _schemaVersion
 
+    @field_validator("version")
+    @classmethod
+    def validate_version(cls, value):
+        """
+        Validate the version field.
+        Args:
+            value: a string representing a version number
+
+        Returns:
+            a fully qualified version number
+
+        Raises:
+            ValueError: if the value is not a valid version number
+        """
+        version = Version.parse(value, optional_minor_and_patch=True)
+        return version.__str__()
+
 
 class _Namespaced(BaseModel):
     """