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, 6 insertions, 4 deletions

diff --git a/docker/AppRun.sh b/docker/AppRun.sh
index f0ae807..e897309 100644
--- a/docker/AppRun.sh
+++ b/docker/AppRun.sh
@@ -89,6 +89,9 @@ if [ -d "${APPIMAGE_DIR}/plugins/plugin_python" ]; then
 fi
 
 # ── Environment ──
+# Save original LD_LIBRARY_PATH so child processes (xdg-open, kde-open, etc.)
+# can use host libraries instead of the bundled (potentially older) ones.
+export FLUORINE_ORIG_LD_LIBRARY_PATH="${LD_LIBRARY_PATH:-}"
 export PATH="${HERE}/usr/bin:${HERE}/usr/libexec:${PATH}"
 export LD_LIBRARY_PATH="${HERE}/usr/lib:${HERE}/usr/libexec:${LD_LIBRARY_PATH:-}"
 
@@ -117,7 +120,7 @@ else
     export MO2_PYTHON_DIR="${APPIMAGE_DIR}/python"
 fi
 # Do not export PYTHONHOME/PYTHONPATH globally here. MO2 sets Python runtime
-# internally for plugin_python, while child processes (umu/NaK/launchers) must
+# internally for plugin_python, while child processes (NaK/launchers) must
 # use their own system Python environment.
 unset PYTHONHOME PYTHONPATH PYTHONNOUSERSITE
 
diff --git a/docker/build-inner.sh b/docker/build-inner.sh
index fa44a60..8b7ac93 100755
--- a/docker/build-inner.sh
+++ b/docker/build-inner.sh
@@ -39,7 +39,6 @@ mkdir -p "${OUT_DIR}/plugins" "${OUT_DIR}/dlls" "${OUT_DIR}/lib"
 
 # ── Main binary + helpers ──
 cp -f "${RUNDIR}/ModOrganizer" "${OUT_DIR}/ModOrganizer-core"
-[ -f "${RUNDIR}/umu-run" ] && cp -f "${RUNDIR}/umu-run" "${OUT_DIR}/umu-run"
 [ -f "${RUNDIR}/README-PORTABLE.txt" ] && cp -f "${RUNDIR}/README-PORTABLE.txt" "${OUT_DIR}/"
 [ -f "/src/src/fluorine-manager" ] && cp -f "/src/src/fluorine-manager" "${OUT_DIR}/"
 
@@ -334,7 +333,7 @@ export MO2_PLUGINS_DIR="${HERE}/plugins"
 export MO2_DLLS_DIR="${HERE}/dlls"
 export MO2_PYTHON_DIR="${PYTHON_DST}"
 # PYTHONHOME is set only for the MO2 process (not exported to children like
-# umu-run/Proton which have their own Python).  MO2_PYTHON_DIR lets the
+# Proton which has its own Python).  MO2_PYTHON_DIR lets the
 # binary reconstruct it internally.
 MO2_PYTHONHOME="${PYTHON_DST}"
 unset PYTHONPATH PYTHONNOUSERSITE PYTHONHOME
@@ -443,7 +442,7 @@ if [ -d "${PYTHON_SRC}" ]; then
 fi
 
 # Save the original (pre-AppImage) environment so game launches can restore it.
-# Without this, AppImage's LD_LIBRARY_PATH/PATH leak into umu-run/Proton and
+# Without this, AppImage's LD_LIBRARY_PATH/PATH leak into Proton and
 # cause library conflicts that make games crash.
 export FLUORINE_ORIG_LD_LIBRARY_PATH="${LD_LIBRARY_PATH:-}"
 export FLUORINE_ORIG_PATH="${PATH}"