Detect native-Linux Stardew Valley, default executables to no-Proton

Add IPluginGame::isNativeLinux() (virtual, default false) so a plugin
can advertise that the discovered installation is a native Linux build.
Bound through the Python plugin trampoline so basic_games subclasses can
override it.

Stardew Valley plugin: when the install dir contains the StardewValley
launcher script and no Stardew Valley.exe, report isNativeLinux=true and
return Linux-side binary names (StardewValley, StardewModdingAPI). Also
fix GameDataPath to "Mods" — Linux ships the SMAPI mods dir with a
capital M.

ExecutablesList::getPluginExecutables: skip the UseProton flag when the
plugin reports native Linux, so the spawn path falls into launchDirect()
and the game runs without a Wine prefix.

2 files changed, 5 insertions, 0 deletions

diff --git a/libs/plugin_python/src/mobase/wrappers/pyplugins.cpp b/libs/plugin_python/src/mobase/wrappers/pyplugins.cpp
index bcce0df..c744c7b 100644
--- a/libs/plugin_python/src/mobase/wrappers/pyplugins.cpp
+++ b/libs/plugin_python/src/mobase/wrappers/pyplugins.cpp
@@ -52,6 +52,7 @@ namespace mo2::python {
                  "settings"_a)
             .def("listSaves", &IPluginGame::listSaves, "folder"_a)
             .def("isInstalled", &IPluginGame::isInstalled)
+            .def("isNativeLinux", &IPluginGame::isNativeLinux)
             .def("gameIcon", &IPluginGame::gameIcon)
             .def("gameDirectory", &IPluginGame::gameDirectory)
             .def("dataDirectory", &IPluginGame::dataDirectory)
diff --git a/libs/plugin_python/src/mobase/wrappers/pyplugins.h b/libs/plugin_python/src/mobase/wrappers/pyplugins.h
index 17f7ab5..ce9a911 100644
--- a/libs/plugin_python/src/mobase/wrappers/pyplugins.h
+++ b/libs/plugin_python/src/mobase/wrappers/pyplugins.h
@@ -385,6 +385,10 @@ namespace mo2::python {
         {
             PYBIND11_OVERRIDE_PURE(bool, IPluginGame, isInstalled, );
         }
+        bool isNativeLinux() const override
+        {
+            PYBIND11_OVERRIDE(bool, IPluginGame, isNativeLinux, );
+        }
         QIcon gameIcon() const override
         {
             PYBIND11_OVERRIDE_PURE(QIcon, IPluginGame, gameIcon, );