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>

1 files changed, 6 insertions, 0 deletions

diff --git a/libs/uibase/include/uibase/registry.h b/libs/uibase/include/uibase/registry.h
index 00013df..6a93f9d 100644
--- a/libs/uibase/include/uibase/registry.h
+++ b/libs/uibase/include/uibase/registry.h
@@ -28,6 +28,12 @@ namespace MOBase
 QDLLEXPORT bool WriteRegistryValue(const QString& appName, const QString& keyName,
                                    const QString& value, const QString& fileName);
 
+// Removes a key from a Bethesda-style INI file without QSettings.
+// Uses a safe line-by-line approach that does not corrupt backslashes
+// or URL-encode spaces in key names.
+QDLLEXPORT bool RemoveRegistryValue(const QString& section, const QString& key,
+                                    const QString& fileName);
+
 #ifdef _WIN32
 // Windows-specific overload using wide strings
 QDLLEXPORT bool WriteRegistryValue(const wchar_t* appName, const wchar_t* keyName,