feat(src/window/screencapture): implement screen capture window with toolbar, tools, and options menu

Added a new window class that integrates with the capture service, provides a toolbar of tool buttons for region, screen, window, and recording modes, includes an options button to toggle settings, and implements save directory selection, delay, cursor, thumbnail, and microphone controls. The implementation follows the existing widget architecture and updates related modules to expose the new functionality.

src/window/screencapture/__init__.py

@@ -0,0 +1,3 @@
+from window.screencapture.main import ScreenCaptureWindow
+
+__all__ = ["ScreenCaptureWindow"]