chore: add Ruff and apply formatting across codebase

Introduce ruff lint/format config, expand .gitignore, and reformat Python sources.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/test_ai_modules.py

@@ -110,9 +110,7 @@ class TestAIParameters:
         assert payload["modalities"] == ["image"]
         assert payload["image_config"] == {"strength": 0.25}
 
-    def test_save_result_matching_source_preserves_png_size(
-        self, tmp_path: Path
-    ) -> None:
+    def test_save_result_matching_source_preserves_png_size(self, tmp_path: Path) -> None:
         try:
             from PIL import Image
         except ImportError: