macOS support (code only, no build yet)

Main.py

@@ -14,7 +14,7 @@ import flet as ft
 import SelfUpdate
 from Catalog import UpdateCatalog
 from Core import (
-    AppName, AppVersion, IsWindows, StartMenuDir, ApplyAppearance, AssetsDir, BuildTheme, BundledFontFamily, ChipButtonStyle, DataDir,
+    AppName, AppVersion, IsLinux, IsMac, IsWindows, StartMenuDir, ApplyAppearance, AssetsDir, BuildTheme, BundledFontFamily, ChipButtonStyle, DataDir,
     BundledManifestsDir, DataHome, EffectiveSettings, LoadConfig, Palette,
 )
 from Dialogs import ShowInstallDialog, ShowOptionsDialog, ShowRemoveDialog, ShowUpdateDialog
@@ -26,7 +26,8 @@ from Settings import ShowSettingsDialog
 _MaxLogLines = 2000
 
 # When running packaged (AppImage / .exe), SaraSuite can put itself in the
-# app menu: a desktop entry on Linux, a Start Menu shortcut on Windows.
+# app menu: a desktop entry on Linux, a Start Menu shortcut on Windows. On
+# macOS SaraSuite.app already is an app wherever it's put (e.g. /Applications).
 _Packaged = SelfUpdate.RunningAppImage()
 _AppImage = str(_Packaged) if _Packaged else ""
 if IsWindows:
@@ -43,7 +44,7 @@ def _KeepFallbackLibraries() -> None:
     ~/.local/share/SaraSuite/Libraries, for FletIdentity.py to give the Flet
     client of every installed program on systems without it."""
     Bundled = Path(getattr(sys, "_MEIPASS", "")) / "FallbackLibs"
-    if IsWindows or not Bundled.is_dir():
+    if not IsLinux or not Bundled.is_dir():
         return
     Kept = DataDir / "Libraries"
     try:
@@ -286,7 +287,7 @@ def Main(Page: ft.Page) -> None:
     MenuButton = ft.OutlinedButton(
         content=f"Remove from {_MenuLabel}" if _MenuEntry.exists() else f"Add to {_MenuLabel}",
         style=ChipButtonStyle(),
-        visible=bool(_AppImage),
+        visible=bool(_AppImage) and not IsMac,
         on_click=ToggleMenuEntry,
     )
 
@@ -355,7 +356,7 @@ if __name__ == "__main__":
 
         sys.exit(Run(sys.argv[1:]))
     SelfUpdate.CleanUpOldExe()
-    if not IsWindows:
+    if IsLinux:
         # A Flet client copy with the window app ID srhtnin.SaraSuite, so the
         # desktop matches the window to SaraSuite.desktop (StartupWMClass) instead
         # of showing it as "com.appveyor.flet". See Programs/FletIdentity.py.