Add Root Builder plugin, Linux game detection, and OMOD installer fix

- New native Root Builder plugin (src/plugins/rootbuilder.py) with copy
  and symlink deploy modes, auto-deploy hooks, backup/restore, and
  third-party conflict detection that moves incompatible plugins to
  DisabledPlugins/. In link mode, .exe/.dll are always copied to avoid
  Wine/Proton path resolution issues with symlinked executables.

- Fix basic_games detection on Linux: steam_utils now checks native
  Steam paths (~/.local/share/Steam, Flatpak, Snap), epic_utils uses
  correct Linux Heroic config paths, gog_utils falls back to Heroic
  GOG installed.json when Windows registry is unavailable.

- Fix OMOD installer crash: isArchiveSupported now handles both IFileTree
  (from mod list refresh) and string (from install check) arguments.

- Add flatpak manifest step to copy source-tree Python plugins
  (src/plugins/*.py) into the build output.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

13 files changed, 202 insertions, 45 deletions

diff --git a/libs/basic_games/epic_utils.py b/libs/basic_games/epic_utils.py
index 94ae6a9..afdccd5 100644
--- a/libs/basic_games/epic_utils.py
+++ b/libs/basic_games/epic_utils.py
@@ -87,6 +87,21 @@ def find_legendary_games(
 
 
 def find_heroic_games(errors: ErrorList | None = None):
+    # Linux: Heroic stores config in ~/.config/heroic/ (or Flatpak equivalent).
+    for candidate in (
+        Path.home() / ".config" / "heroic" / "legendaryConfig",
+        Path.home()
+        / ".var"
+        / "app"
+        / "com.heroicgameslauncher.hgl"
+        / "config"
+        / "heroic"
+        / "legendaryConfig",
+    ):
+        if candidate.is_dir():
+            return find_legendary_games(str(candidate), errors)
+
+    # Windows fallback.
     return find_legendary_games(
         os.path.expandvars(r"%AppData%\heroic\legendaryConfig"), errors
     )
diff --git a/libs/basic_games/gog_utils.py b/libs/basic_games/gog_utils.py
index e5e6d24..de66ec2 100644
--- a/libs/basic_games/gog_utils.py
+++ b/libs/basic_games/gog_utils.py
@@ -1,12 +1,50 @@
 # Code adapted from EzioTheDeadPoet / erri120:
 #     https://github.com/ModOrganizer2/modorganizer-basic_games/pull/5
 
+from __future__ import annotations
+
+import json
+import sys
 import winreg
 from pathlib import Path
 
 
+def _find_heroic_gog_games() -> dict[str, Path]:
+    """Detect GOG games installed via Heroic Launcher on Linux."""
+    games: dict[str, Path] = {}
+
+    for candidate in (
+        Path.home() / ".config" / "heroic" / "gog_store" / "installed.json",
+        Path.home()
+        / ".var"
+        / "app"
+        / "com.heroicgameslauncher.hgl"
+        / "config"
+        / "heroic"
+        / "gog_store"
+        / "installed.json",
+    ):
+        if not candidate.is_file():
+            continue
+        try:
+            with open(candidate, encoding="utf-8") as f:
+                data = json.load(f)
+            for game in data.get("installed", []):
+                app_name = game.get("appName", "")
+                install_path = game.get("install_path") or game.get("installPath", "")
+                if app_name and install_path:
+                    games[str(app_name)] = Path(install_path)
+        except (json.JSONDecodeError, OSError) as e:
+            print(
+                f'Unable to parse Heroic GOG installed games from "{candidate}": {e}',
+                file=sys.stderr,
+            )
+
+    return games
+
+
 def find_games() -> dict[str, Path]:
-    # List the game IDs from the registry:
+    # List the game IDs from the registry (Windows):
     game_ids: list[str] = []
     try:
         with winreg.OpenKey(
@@ -18,7 +56,8 @@ def find_games() -> dict[str, Path]:
                 if game_key.isdigit():
                     game_ids.append(game_key)
     except FileNotFoundError:
-        return {}
+        # Windows registry not available; try Heroic GOG on Linux.
+        return _find_heroic_gog_games()
 
     # For each game, query the path:
     games: dict[str, Path] = {}
diff --git a/libs/basic_games/steam_utils.py b/libs/basic_games/steam_utils.py
index d1d4a06..a3daeaf 100644
--- a/libs/basic_games/steam_utils.py
+++ b/libs/basic_games/steam_utils.py
@@ -148,7 +148,28 @@ def find_steam_path() -> Path | None:
             value = winreg.QueryValueEx(key, "SteamExe")
             return Path(value[0].replace("/", "\\")).parent
     except FileNotFoundError:
-        return None
+        pass
+
+    # Linux: check common Steam install locations.
+    for candidate in (
+        Path.home() / ".local" / "share" / "Steam",
+        Path.home() / ".steam" / "steam",
+        Path.home()
+        / ".var"
+        / "app"
+        / "com.valvesoftware.Steam"
+        / ".local"
+        / "share"
+        / "Steam",
+        Path.home() / "snap" / "steam" / "common" / ".local" / "share" / "Steam",
+    ):
+        if (
+            candidate.is_dir()
+            and candidate.joinpath("steamapps", "libraryfolders.vdf").exists()
+        ):
+            return candidate
+
+    return None
 
 
 def find_games() -> dict[str, Path]:
diff --git a/libs/game_bethesda/src/gamebryo/gamegamebryo.cpp b/libs/game_bethesda/src/gamebryo/gamegamebryo.cpp
index ac9fe22..bcb29f2 100644
--- a/libs/game_bethesda/src/gamebryo/gamegamebryo.cpp
+++ b/libs/game_bethesda/src/gamebryo/gamegamebryo.cpp
@@ -1,5 +1,7 @@
 #include "gamegamebryo.h"
 
+#include <uibase/filesystemutilities.h>
+
 #include "bsainvalidation.h"
 #include "dataarchives.h"
 #include "gamebryomoddatacontent.h"
@@ -44,37 +46,8 @@
 #include <string>
 #include <vector>
 
-// Case-insensitive file path resolution for Linux.
-// On Windows (case-insensitive FS), just returns the input path.
-// On Linux, if the exact path doesn't exist, searches the parent directory
-// for a file matching the name case-insensitively.
-static QString resolveFileCaseInsensitive(const QString& filePath)
-{
-#ifdef _WIN32
-  return filePath;
-#else
-  if (QFileInfo::exists(filePath)) {
-    return filePath;
-  }
-
-  QFileInfo info(filePath);
-  QDir dir(info.path());
-  if (!dir.exists()) {
-    return filePath;
-  }
-
-  const QString target = info.fileName();
-  const QStringList entries =
-      dir.entryList(QDir::Files | QDir::Hidden | QDir::System);
-  for (const QString& entry : entries) {
-    if (entry.compare(target, Qt::CaseInsensitive) == 0) {
-      return dir.absoluteFilePath(entry);
-    }
-  }
-
-  return filePath;
-#endif
-}
+// Local resolveFileCaseInsensitive moved to MOBase::resolveFileCaseInsensitive
+using MOBase::resolveFileCaseInsensitive;
 
 GameGamebryo::GameGamebryo() {}
 
diff --git a/libs/installer_fomod/src/fomodinstallerdialog.cpp b/libs/installer_fomod/src/fomodinstallerdialog.cpp
index ef6c44f..0fa6bfc 100644
--- a/libs/installer_fomod/src/fomodinstallerdialog.cpp
+++ b/libs/installer_fomod/src/fomodinstallerdialog.cpp
@@ -77,12 +77,13 @@ bool PagesDescending(QGroupBox* LHS, QGroupBox* RHS)
 
 FomodInstallerDialog::FomodInstallerDialog(
     InstallerFomod* installer, const GuessedValue<QString>& modName,
-    const QString& fomodPath,
+    const QString& fomodPath, const QString& fomodDirName,
     const std::function<MOBase::IPluginList::PluginStates(const QString&)>& fileCheck,
     QWidget* parent)
     : QDialog(parent), ui(new Ui::FomodInstallerDialog), m_Installer(installer),
-      m_ModName(modName), m_ModID(-1), m_FomodPath(fomodPath), m_Manual(false),
-      m_FileCheck(fileCheck), m_FileSystemItemSequence()
+      m_ModName(modName), m_ModID(-1), m_FomodPath(fomodPath),
+      m_FomodDirName(fomodDirName), m_Manual(false), m_FileCheck(fileCheck),
+      m_FileSystemItemSequence()
 {
   ui->setupUi(this);
   setWindowFlags(windowFlags() | Qt::WindowMaximizeButtonHint);
@@ -235,7 +236,7 @@ void FomodInstallerDialog::readXml(QFile& file,
 
 void FomodInstallerDialog::readInfoXml()
 {
-  QFile file(QDir::tempPath() + "/" + m_FomodPath + "/fomod/info.xml");
+  QFile file(QDir::tempPath() + "/" + m_FomodPath + "/" + m_FomodDirName + "/info.xml");
 
   // We don't need a info.xml file, so we just return if we cannot open it:
   if (!file.open(QIODevice::ReadOnly)) {
@@ -246,7 +247,7 @@ void FomodInstallerDialog::readInfoXml()
 
 void FomodInstallerDialog::readModuleConfigXml()
 {
-  QFile file(QDir::tempPath() + "/" + m_FomodPath + "/fomod/ModuleConfig.xml");
+  QFile file(QDir::tempPath() + "/" + m_FomodPath + "/" + m_FomodDirName + "/ModuleConfig.xml");
   if (!file.open(QIODevice::ReadOnly)) {
     throw Exception(tr("%1 missing.").arg(file.fileName()));
   }
@@ -261,7 +262,7 @@ void FomodInstallerDialog::initData(IOrganizer* moInfo)
   readInfoXml();
 
   QString screenshotPath =
-      QDir::tempPath() + "/" + m_FomodPath + "/fomod/screenshot.png";
+      QDir::tempPath() + "/" + m_FomodPath + "/" + m_FomodDirName + "/screenshot.png";
   if (!QImage(screenshotPath).isNull()) {
     ui->screenshotLabel->setScalableResource(screenshotPath);
     ui->screenshotExpand->setVisible(false);
diff --git a/libs/installer_fomod/src/fomodinstallerdialog.h b/libs/installer_fomod/src/fomodinstallerdialog.h
index bd9f975..1ebfe60 100644
--- a/libs/installer_fomod/src/fomodinstallerdialog.h
+++ b/libs/installer_fomod/src/fomodinstallerdialog.h
@@ -209,7 +209,7 @@ class FomodInstallerDialog : public QDialog, public IConditionTester
 public:
   explicit FomodInstallerDialog(
       InstallerFomod* installer, const MOBase::GuessedValue<QString>& modName,
-      const QString& fomodPath,
+      const QString& fomodPath, const QString& fomodDirName,
       const std::function<MOBase::IPluginList::PluginStates(const QString&)>& fileCheck,
       QWidget* parent = 0);
   ~FomodInstallerDialog();
@@ -453,6 +453,7 @@ private:
   int m_ModID;
 
   QString m_FomodPath;
+  QString m_FomodDirName;
   bool m_Manual;
 
   FileDescriptorList m_RequiredFiles;
diff --git a/libs/installer_fomod/src/installerfomod.cpp b/libs/installer_fomod/src/installerfomod.cpp
index 3558748..8be3ca3 100644
--- a/libs/installer_fomod/src/installerfomod.cpp
+++ b/libs/installer_fomod/src/installerfomod.cpp
@@ -217,8 +217,9 @@ InstallerFomod::install(GuessedValue<QString>& modName,
       std::shared_ptr<const IFileTree> fomodTree = findFomodDirectory(tree);
 
       QString fomodPath = fomodTree->parent()->path();
+      QString fomodDirName = fomodTree->name();
       FomodInstallerDialog dialog(
-          this, modName, fomodPath,
+          this, modName, fomodPath, fomodDirName,
           std::bind(&InstallerFomod::fileState, this, std::placeholders::_1));
       dialog.initData(m_MOInfo);
       if (!dialog.getVersion().isEmpty()) {
diff --git a/libs/nak_ffi/Cargo.lock b/libs/nak_ffi/Cargo.lock
index af0ac00..83d19cc 100644
--- a/libs/nak_ffi/Cargo.lock
+++ b/libs/nak_ffi/Cargo.lock
@@ -1129,7 +1129,7 @@ dependencies = [
 [[package]]
 name = "nak_rust"
 version = "4.4.1"
-source = "git+https://github.com/SulfurNitride/NaK.git?branch=main#ceea41b64e6cafb8375978d7982e2c46fe826047"
+source = "git+https://github.com/SulfurNitride/NaK.git?branch=main#41915b5a095da6bc5b4960eac2c9e55771caa7c4"
 dependencies = [
  "chrono",
  "rand",
diff --git a/libs/nak_ffi/Cargo.toml b/libs/nak_ffi/Cargo.toml
index 000297c..fc667e0 100644
--- a/libs/nak_ffi/Cargo.toml
+++ b/libs/nak_ffi/Cargo.toml
@@ -6,5 +6,5 @@ edition = "2021"
 [lib]

 crate-type = ["cdylib"]

 

-[dependencies]
-nak_rust = { git = "https://github.com/SulfurNitride/NaK.git", branch = "main", default-features = false, features = ["installer"] }
+[dependencies]

+nak_rust = { git = "https://github.com/SulfurNitride/NaK.git", branch = "main", default-features = false, features = ["installer"] }

diff --git a/libs/nak_ffi/include/nak_ffi.h b/libs/nak_ffi/include/nak_ffi.h
index c6010d4..df4d47b 100644
--- a/libs/nak_ffi/include/nak_ffi.h
+++ b/libs/nak_ffi/include/nak_ffi.h
@@ -194,6 +194,18 @@ char *nak_apply_wine_registry_settings(
     uint32_t app_id

 );

 

+/** Apply a game's registry entry with a custom install path.

+ *  Looks up game_name in KNOWN_GAMES and writes registry pointing to install_path.

+ *  Returns NULL on success, or an error message (free with nak_string_free). */

+char *nak_apply_registry_for_game_path(

+    const char *prefix_path,

+    const char *proton_name,

+    const char *proton_path,

+    const char *game_name,

+    const char *install_path,

+    NakLogCallback log_cb

+);

+

 /* ========================================================================

  * Tier 7: Prefix Symlinks

  * ======================================================================== */

diff --git a/libs/nak_ffi/src/lib.rs b/libs/nak_ffi/src/lib.rs
index 0e7b4f3..2e19af7 100644
--- a/libs/nak_ffi/src/lib.rs
+++ b/libs/nak_ffi/src/lib.rs
@@ -659,6 +659,58 @@ pub unsafe extern "C" fn nak_apply_wine_registry_settings(
     }

 }

 

+/// Apply a game's registry entry with a custom install path.

+///

+/// Looks up the game by name in KNOWN_GAMES, writes the registry entry

+/// pointing to `install_path`. Returns null on success, or an error message.

+#[no_mangle]

+pub unsafe extern "C" fn nak_apply_registry_for_game_path(

+    prefix_path: *const c_char,

+    proton_name: *const c_char,

+    proton_path: *const c_char,

+    game_name: *const c_char,

+    install_path: *const c_char,

+    log_cb: NakLogCallback,

+) -> *mut c_char {

+    let prefix = unsafe { from_cstr(prefix_path) };

+    let _proton_name = unsafe { from_cstr(proton_name) };

+    let proton_path_str = unsafe { from_cstr(proton_path) };

+    let game = unsafe { from_cstr(game_name) };

+    let install = unsafe { from_cstr(install_path) };

+

+    let protons = nak_rust::steam::find_steam_protons();

+    let proton = match protons

+        .iter()

+        .find(|p| p.path.to_string_lossy() == proton_path_str)

+    {

+        Some(p) => p.clone(),

+        None => {

+            return to_cstring(&format!(

+                "Proton not found at path: {}",

+                proton_path_str

+            ));

+        }

+    };

+

+    let log_fn = move |msg: String| {

+        if let Some(cb) = log_cb {

+            let c = CString::new(msg).unwrap_or_default();

+            unsafe { cb(c.as_ptr()) };

+        }

+    };

+

+    match nak_rust::installers::apply_registry_for_game_path(

+        Path::new(prefix),

+        &proton,

+        game,

+        Path::new(install),

+        &log_fn,

+    ) {

+        Ok(()) => ptr::null_mut(),

+        Err(e) => to_cstring(&e),

+    }

+}

+

 // ============================================================================

 // Tier 7: Prefix Symlinks

 // ============================================================================

diff --git a/libs/uibase/include/uibase/filesystemutilities.h b/libs/uibase/include/uibase/filesystemutilities.h
index ae074c6..a98ba7b 100644
--- a/libs/uibase/include/uibase/filesystemutilities.h
+++ b/libs/uibase/include/uibase/filesystemutilities.h
@@ -31,6 +31,18 @@ QDLLEXPORT QString sanitizeFileName(const QString& name,
  **/
 QDLLEXPORT bool validFileName(const QString& name);
 
+/**
+ * @brief Resolve a file path case-insensitively on Linux.
+ *
+ * On Windows (case-insensitive FS), returns the input path as-is.
+ * On Linux, if the exact path doesn't exist, searches the parent directory
+ * for a file matching the name case-insensitively.
+ *
+ * @param path the absolute file path to resolve
+ * @return the resolved path (with correct case) or the original path if not found
+ */
+QDLLEXPORT QString resolveFileCaseInsensitive(const QString& path);
+
 }  // namespace MOBase
 
 #endif  // FILESYSTEM_H
diff --git a/libs/uibase/src/filesystemutilities.cpp b/libs/uibase/src/filesystemutilities.cpp
index 6a01324..b027f5f 100644
--- a/libs/uibase/src/filesystemutilities.cpp
+++ b/libs/uibase/src/filesystemutilities.cpp
@@ -1,5 +1,7 @@
 #include <uibase/filesystemutilities.h>
 
+#include <QDir>
+#include <QFileInfo>
 #include <QRegularExpression>
 #include <QString>
 
@@ -65,4 +67,32 @@ bool validFileName(const QString& name)
   return (name == sanitizeFileName(name));
 }
 
+QString resolveFileCaseInsensitive(const QString& path)
+{
+#ifdef _WIN32
+  return QDir::cleanPath(path);
+#else
+  const QFileInfo info(path);
+  if (info.exists()) {
+    return info.absoluteFilePath();
+  }
+
+  QDir dir(info.path());
+  if (!dir.exists()) {
+    return QDir::cleanPath(path);
+  }
+
+  const QString target = info.fileName();
+  const QStringList entries =
+      dir.entryList(QDir::Files | QDir::Readable | QDir::Hidden | QDir::System);
+  for (const QString& entry : entries) {
+    if (entry.compare(target, Qt::CaseInsensitive) == 0) {
+      return dir.absoluteFilePath(entry);
+    }
+  }
+
+  return QDir::cleanPath(path);
+#endif
+}
+
 }  // namespace MOBase