Remove umu-run, keep game as child process for Steam tracking

- Remove umu-run entirely (crashed due to pressure-vessel/FUSE
  incompatibility) — use raw `proton run` instead
- Replace startDetached() with QProcess::start() so the game stays in
  Fluorine's process tree. This lets Steam track the game lifetime and
  makes the "close game" button work when Fluorine is added as a
  non-Steam game.
- Add writeIniValueDirect/readIniValueDirect for safe Bethesda INI
  handling without QSettings corruption
- Fix prefix_setup.rs to skip umu-run bootstrapping
- Clean up settings UI, build scripts, and docs for umu-run removal

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

2 files changed, 22 insertions, 20 deletions

diff --git a/libs/game_bethesda/src/gamebryo/gamebryolocalsavegames.cpp b/libs/game_bethesda/src/gamebryo/gamebryolocalsavegames.cpp
index 4c1199c..2daf2c3 100644
--- a/libs/game_bethesda/src/gamebryo/gamebryolocalsavegames.cpp
+++ b/libs/game_bethesda/src/gamebryo/gamebryolocalsavegames.cpp
@@ -23,21 +23,8 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 #include <stddef.h>
 #include <string>
 
-#include <QSettings>
-
 #include "gamegamebryo.h"
 
-// Helper to remove a key from a Bethesda-style INI file
-static void removeIniValue(const QString& iniFile, const QString& section,
-                           const QString& key)
-{
-  QSettings settings(iniFile, QSettings::IniFormat);
-  settings.beginGroup(section);
-  settings.remove(key);
-  settings.endGroup();
-  settings.sync();
-}
-
 GamebryoLocalSavegames::GamebryoLocalSavegames(const GameGamebryo* game,
                                                const QString& iniFileName)
     : m_Game{game}, m_IniFileName(iniFileName)
@@ -119,20 +106,20 @@ bool GamebryoLocalSavegames::prepareProfile(MOBase::IProfile* profile)
       if (savedPath != "DELETE_ME") {
         MOBase::WriteRegistryValue("General", "sLocalSavePath", savedPath, iniFilePath);
       } else {
-        removeIniValue(iniFilePath, "General", "sLocalSavePath");
+        MOBase::RemoveRegistryValue("General", "sLocalSavePath", iniFilePath);
       }
       if (savedMyGames != "DELETE_ME") {
         MOBase::WriteRegistryValue("General", "bUseMyGamesDirectory", savedMyGames,
                                    iniFilePath);
       } else {
-        removeIniValue(iniFilePath, "General", "bUseMyGamesDirectory");
+        MOBase::RemoveRegistryValue("General", "bUseMyGamesDirectory", iniFilePath);
       }
       QFile::remove(saveIni);
     }
     // Otherwise just delete the setting
     else {
-      removeIniValue(iniFilePath, "General", "sLocalSavePath");
-      removeIniValue(iniFilePath, "General", "bUseMyGamesDirectory");
+      MOBase::RemoveRegistryValue("General", "sLocalSavePath", iniFilePath);
+      MOBase::RemoveRegistryValue("General", "bUseMyGamesDirectory", iniFilePath);
     }
   }
 
diff --git a/libs/game_bethesda/src/gamebryo/gamegamebryo.cpp b/libs/game_bethesda/src/gamebryo/gamegamebryo.cpp
index 4a92440..2fd45cd 100644
--- a/libs/game_bethesda/src/gamebryo/gamegamebryo.cpp
+++ b/libs/game_bethesda/src/gamebryo/gamegamebryo.cpp
@@ -357,6 +357,15 @@ void GameGamebryo::ensureIniFilesExist(const QString& basePath)
     }
 
 #ifndef _WIN32
+    // Remove broken symlinks — QFileInfo::exists() follows symlinks and
+    // returns false for dangling ones, but QFile::copy() fails with
+    // "File exists" because the symlink inode is still there.
+    if (targetInfo.isSymLink() && !targetInfo.exists()) {
+      QFile::remove(targetPath);
+    }
+#endif
+
+#ifndef _WIN32
     // On Linux, search for a differently-cased version of this INI file
     // (e.g., FalloutPrefs.ini when we expect falloutprefs.ini).
     // We can't use resolveFileCaseInsensitive here because the exact-case
@@ -413,15 +422,21 @@ void GameGamebryo::ensureIniFilesExist(const QString& basePath)
       if (targetInfo.exists()) {
         QFile::remove(targetPath);
       }
-      if (QFile::copy(defaultIniPath, targetPath)) {
+      QFile srcFile(defaultIniPath);
+      if (srcFile.copy(targetPath)) {
         // Make the copy writable
         QFile::setPermissions(
             targetPath,
             QFile::permissions(targetPath) | QFile::WriteUser | QFile::WriteOwner);
         MOBase::log::info("Seeded '{}' from default INI '{}'", iniFile, defaultIniPath);
       } else {
-        MOBase::log::warn("Failed to copy default INI '{}' -> '{}'",
-                          defaultIniPath, targetPath);
+        MOBase::log::warn("Failed to copy default INI '{}' -> '{}': {} "
+                          "(srcExists={}, srcSize={}, targetExists={}, dirExists={})",
+                          defaultIniPath, targetPath, srcFile.errorString(),
+                          QFileInfo::exists(defaultIniPath),
+                          QFileInfo(defaultIniPath).size(),
+                          QFileInfo::exists(targetPath),
+                          QFileInfo(targetPath).dir().exists());
       }
     }