feat: PySide6 dev environment with runnable examplesHEADmain

Flake devShell (PySide6 6.11 on Python 3.13, designer, uic/rcc from
qtbase libexec, offline docs) plus hello_widgets and hello_quick
examples. QML_IMPORT_PATH exported — nixpkgs PySide6 finds platform
plugins on its own but not QML imports; see README.

1 files changed, 43 insertions, 0 deletions

diff --git a/examples/hello_widgets.py b/examples/hello_widgets.py
new file mode 100644
index 0000000..926fff6
--- /dev/null
+++ b/examples/hello_widgets.py
@@ -0,0 +1,43 @@
+#!/usr/bin/env python3
+"""Minimal PySide6 Widgets app: a counter demonstrating signals/slots."""
+
+import sys
+
+from PySide6.QtWidgets import (
+    QApplication,
+    QLabel,
+    QPushButton,
+    QVBoxLayout,
+    QWidget,
+)
+
+
+def main() -> int:
+    app = QApplication(sys.argv)
+
+    window = QWidget()
+    window.setWindowTitle("Hello PySide6")
+
+    label = QLabel("Clics : 0")
+    button = QPushButton("Cliquer")
+
+    count = 0
+
+    def on_click() -> None:
+        nonlocal count
+        count += 1
+        label.setText(f"Clics : {count}")
+
+    button.clicked.connect(on_click)
+
+    layout = QVBoxLayout(window)
+    layout.addWidget(label)
+    layout.addWidget(button)
+
+    window.resize(240, 100)
+    window.show()
+    return app.exec()
+
+
+if __name__ == "__main__":
+    sys.exit(main())