fix(studio): Qt6 compat + Ctrl+C signal handler

- flash_console: setTextFormat(Qt.TextFormat.RichText) — int overload removed in Qt6
- installer_widget: same fix + add Qt to QtCore import
- project_editor/installer_widget: Session.has() → Session.can()
- app.py: signal.signal(SIGINT, SIG_DFL) so Ctrl+C kills the process from terminal

AR_electronics — AR-Autopilot Project

arautopilot/studio/app.py

@@ -80,6 +80,9 @@ def run(argv: list[str] | None = None) -> int:
     from arautopilot.studio.login_window import LoginDialog
     from arautopilot.studio.main_window import StudioMainWindow
 
+    import signal  # noqa: PLC0415
+    signal.signal(signal.SIGINT, signal.SIG_DFL)  # Ctrl+C kills the process
+
     app = QApplication(sys.argv)
     app.setApplicationName("AR-Autopilot Studio")