feat: rewrite validation, rename built-in vars, bump python version

pyproject.toml

@@ -1,7 +1,7 @@
 [project]
 name = "lohup"
 version = "0.1.0"
-description = "Backups done dummy"
+description = "Backups done silly"
 readme = "README.md"
 maintainers = [
     {name = "Igor Ovsyannikov"}
@@ -16,7 +16,7 @@ classifiers = [
     "Topic :: System :: Archiving :: Backup",
     "Topic :: Utilities",
 ]
-requires-python = ">=3.13"
+requires-python = ">=3.14"
 dependencies = [
     "click>=8.2.1",
     "humanize>=4.13.0",
@@ -28,8 +28,8 @@ Repository = "https://github.com/kam1sh/lohup"
 
 [dependency-groups]
 dev = [
-    "pyinstaller>=6.15.0",
-    "pytest>=8.4.1",
+    "pyinstaller>=6.21.0",
+    "pytest>=9.1.1",
 ]
 
 [project.scripts]