style: adopt ruff (format + lint) at 88, replacing black/isort/flake8

Format-only: Python files are AST-identical apart from import order.
pre-commit end-of-file/trailing-whitespace fixes applied repo-wide.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

app_skellington/app_container.py

@@ -4,13 +4,13 @@ import os
 
 import appdirs
 
-from ._util import ServiceNotFound, NoCommandSpecified, get_root_asset
 from . import log
-from .cfg import Config
-from .cli import CommandTree
 
 # Application scaffolding:
 from ._bootstrap import _bootstrap_logger
+from ._util import NoCommandSpecified, ServiceNotFound, get_root_asset
+from .cfg import Config
+from .cli import CommandTree
 
 # These two variables affect the directory paths for
 # config files and logging.
@@ -189,5 +189,3 @@ class ApplicationContainer:
     def usage(self):
         pass
         # Applications need a default usage
-
-

app_skellington/cfg.py

@@ -217,9 +217,9 @@ class Config:
         try:
             _bootstrap_logger.info("cfg - Validating config file against spec")
             val = validate.Validator()
-            assert isinstance(
-                self._config_obj, configobj.ConfigObj
-            ), "expecting configobj.ConfigObj, received %s" % type(self._config_obj)
+            assert isinstance(self._config_obj, configobj.ConfigObj), (
+                "expecting configobj.ConfigObj, received %s" % type(self._config_obj)
+            )
             # NOTE(MG) copy arg below instructs configobj to use defaults from spec file
             test_results = self._config_obj.validate(
                 val, copy=True, preserve_errors=True

app_skellington/cli.py

@@ -3,8 +3,8 @@ import inspect
 import re
 import sys
 
-from ._util import NoCommandSpecified
 from ._bootstrap import _bootstrap_logger
+from ._util import NoCommandSpecified
 
 # If explicit fail is enabled, any command with at least one unknown
 # argument will be rejected entirely. If not enabled, unknown arguments
@@ -233,22 +233,21 @@ class CommandTree:
         # the CommandTree with no SubMenu (submenu will be disabled
         # in this case):
         if self._cmd_tree_is_single_command:
-            assert (
-                self._cmd_tree_is_single_command is True
-            ), "corrupt data structure in CommandMenu"
+            assert self._cmd_tree_is_single_command is True, (
+                "corrupt data structure in CommandMenu"
+            )
             assert self._entries is None, "corrupt data structure in CommandMenu"
-            assert isinstance(
-                self._single_command, CommandEntry
-            ), "corrupt data structure in CommandMenu"
+            assert isinstance(self._single_command, CommandEntry), (
+                "corrupt data structure in CommandMenu"
+            )
             return self._single_command
 
         # There is at least one submenu we need to go down:
         else:
-
             assert self._single_command is None, "corrupt data structure in CommandMenu"
-            assert (
-                self._cmd_tree_is_single_command is False
-            ), "corrupt data structure in CommandMenu"
+            assert self._cmd_tree_is_single_command is False, (
+                "corrupt data structure in CommandMenu"
+            )
 
             # Key or variable name used by argparse to store the submenu options
             argparse_param = self.submenu_param  # e.g.: submenu_root