Fix compatibility issues with Qt/PyQt6 versions

- Add null check for message.message in search filter
- Handle missing colorScheme/colorSchemeChanged methods for older Qt versions
- Add display check to prevent hanging in headless environments
- Update build documentation with system package alternative
- Update PyInstaller spec for Python 3.12
- Improve run.sh script with venv management

gotify_tray/gui/themes/__init__.py

@@ -3,14 +3,21 @@ from gotify_tray.utils import get_abs_path
 
 
 themes = {
-    QtCore.Qt.ColorScheme.Dark: "dark",
-    QtCore.Qt.ColorScheme.Light: "light",
-    QtCore.Qt.ColorScheme.Unknown: "light",
+    2: "dark",  # Dark
+    1: "light",  # Light
+    0: "light",  # Unknown
 }
 
 
 def set_theme(app: QtWidgets.QApplication):
-    theme = themes.get(app.styleHints().colorScheme(), "light")
+    if hasattr(app.styleHints(), "colorScheme"):
+        color_scheme = app.styleHints().colorScheme()
+        theme = themes.get(
+            color_scheme.value if hasattr(color_scheme, "value") else color_scheme,
+            "light",
+        )
+    else:
+        theme = "light"  # Default to light theme if colorScheme not available
 
     stylesheet = ""
     with open(get_abs_path(f"gotify_tray/gui/themes/base.qss"), "r") as f:
@@ -23,5 +30,12 @@ def set_theme(app: QtWidgets.QApplication):
 
 def get_theme_file(file: str) -> str:
     app = QtCore.QCoreApplication.instance()
-    theme = themes.get(app.styleHints().colorScheme(), "light")
+    if hasattr(app.styleHints(), "colorScheme"):
+        color_scheme = app.styleHints().colorScheme()
+        theme = themes.get(
+            color_scheme.value if hasattr(color_scheme, "value") else color_scheme,
+            "light",
+        )
+    else:
+        theme = "light"  # Default to light theme if colorScheme not available
     return get_abs_path(f"gotify_tray/gui/themes/{theme}/{file}")