feat: implement core functionality for camera preview application

- Add FrameDispatcher for distributing QVideoFrames to subscribers
- Implement TelemetryCollector to measure video pipeline performance metrics
- Create MainWindow as the main application interface with video rendering
- Develop AppMenuBar for camera selection, resolution, and FPS settings
- Establish overlay system for displaying telemetry metrics
- Set up project structure and configuration files
- Add unit tests for FrameDispatcher and TelemetryCollector

app/main.py

@@ -0,0 +1,35 @@
+"""Application entry point."""
+
+from __future__ import annotations
+
+import logging
+import sys
+
+from PySide6.QtCore import Qt
+from PySide6.QtWidgets import QApplication
+
+from app.config import APP_NAME
+from app.ui.main_window import MainWindow
+
+
+def main() -> None:
+    # Basic logging — WARNING by default; Debug menu toggles to DEBUG
+    logging.basicConfig(
+        level=logging.WARNING,
+        format="%(asctime)s [%(levelname)s] %(name)s: %(message)s",
+    )
+
+    app = QApplication(sys.argv)
+    app.setApplicationName(APP_NAME)
+    app.setHighDpiScaleFactorRoundingPolicy(
+        Qt.HighDpiScaleFactorRoundingPolicy.PassThrough
+    )
+
+    window = MainWindow()
+    window.show()
+
+    sys.exit(app.exec())
+
+
+if __name__ == "__main__":
+    main()