Add Pydantic; new validation from specs

Author: vdusek

pyproject.toml

@@ -29,6 +29,7 @@ dependencies = [
     "colorama>=0.4.0",
     "impit>=0.9.2",
     "more_itertools>=10.0.0",
+    "pydantic[email]>=2.11.0",
 ]
 
 [project.urls]
@@ -144,6 +145,7 @@ indent-style = "space"
     "D",      # Everything from the pydocstyle
     "E501",   # Line too long
     "ERA001", # Commented-out code
+    "TC003",  # Move standard library import into a type-checking block
 ]
 
 [tool.ruff.lint.flake8-quotes]
@@ -172,10 +174,7 @@ python-version = "3.10"
 include = ["src", "tests", "scripts", "docs", "website"]
 
 [[tool.ty.overrides]]
-include = [
-    "docs/**/*.py",
-    "website/**/*.py",
-]
+include = ["docs/**/*.py", "website/**/*.py"]
 
 [tool.ty.overrides.rules]
 unresolved-import = "ignore"