FUSE VFS performance, tracked writes fix, remove steam-run, add NixOS flake

- FUSE: disable AUTO_INVAL_DATA, enable readdirplus, 24h TTLs, clone_fd,
  FUSE_USE_VERSION=312 — cuts game load time from 2:40 to 1:57
- Fix tracked writes going to wrong (lower-priority) mod in both
  detectManualMoves and syncOverwrite
- Remove steam-run entirely (UI, C++, Rust layers)
- Build system: default to tarball, add installer/appimage as opt-in modes
- Add flake.nix for NixOS — builds from source with Rust crates as
  separate pure derivations, FHS wrapper, NixOS module with FUSE passthrough

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

1 files changed, 574 insertions, 0 deletions

diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..192f3ee
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,574 @@
+{
+  description = "Fluorine Manager — Mod Organizer 2 for Linux";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+  };
+
+  outputs = { self, nixpkgs }:
+    let
+      system = "x86_64-linux";
+      pkgs = import nixpkgs { inherit system; };
+
+      version = "0.1.0";
+      pythonVersion = "3.13";
+      portablePythonVersion = "3.13.9";
+
+      # ── libloot (not in nixpkgs — build from source) ──
+      libloot = pkgs.stdenv.mkDerivation {
+        pname = "libloot";
+        version = "0.29.0";
+
+        src = pkgs.fetchFromGitHub {
+          owner = "loot";
+          repo = "libloot";
+          rev = "master";
+          hash = "";  # nix will tell you the correct hash on first build
+          fetchSubmodules = true;
+        };
+
+        nativeBuildInputs = with pkgs; [ cmake ninja ];
+
+        cmakeDir = "../cpp";
+        cmakeFlags = [
+          "-DBUILD_SHARED_LIBS=ON"
+          "-DLIBLOOT_INSTALL_DOCS=OFF"
+          "-DBUILD_TESTING=OFF"
+        ];
+
+        postInstall = ''
+          mkdir -p $out/lib/pkgconfig
+          cat > $out/lib/pkgconfig/libloot.pc <<EOF
+          prefix=$out
+          exec_prefix=''${prefix}
+          libdir=''${prefix}/lib
+          includedir=''${prefix}/include
+
+          Name: libloot
+          Description: LOOT C++ API library
+          Version: 0.29.0
+          Libs: -L''${libdir} -lloot
+          Cflags: -I''${includedir}
+          EOF
+        '';
+      };
+
+      # ── Rust FFI crates (built separately, then injected into cmake) ──
+
+      # bsa_ffi is self-contained (no local path deps).
+      bsa-ffi = pkgs.rustPlatform.buildRustPackage {
+        pname = "bsa-ffi";
+        inherit version;
+
+        src = ./libs/bsa_ffi;
+        cargoLock.lockFile = ./libs/bsa_ffi/Cargo.lock;
+
+        # Output is a cdylib (.so).
+        installPhase = ''
+          mkdir -p $out/lib
+          cp target/release/libbsa_ffi.so $out/lib/
+        '';
+      };
+
+      # nak_ffi depends on nak_rust via `path = "../nak"`.  We give
+      # rustPlatform the parent directory so both crates are visible,
+      # and build only nak_ffi.
+      nak-ffi = pkgs.rustPlatform.buildRustPackage {
+        pname = "nak-ffi";
+        inherit version;
+
+        # Source must include both libs/nak and libs/nak_ffi.
+        src = pkgs.lib.cleanSourceWith {
+          src = ./libs;
+          filter = path: type:
+            let baseName = builtins.baseNameOf path; in
+            # Include nak/ and nak_ffi/ directories (and their contents).
+            builtins.match ".*/libs/(nak|nak_ffi)(/.*|$)" path != null
+            # Also include the top-level libs/ dir itself.
+            || type == "directory" && baseName == "libs";
+        };
+
+        sourceRoot = "source/nak_ffi";
+        cargoLock.lockFile = ./libs/nak_ffi/Cargo.lock;
+
+        installPhase = ''
+          mkdir -p $out/lib
+          cp target/release/libnak_ffi.so $out/lib/
+        '';
+      };
+
+      # ── Portable Python runtime (bundled, not for compilation) ──
+      portable-python = pkgs.fetchzip {
+        url = "https://github.com/bjia56/portable-python/releases/download/cpython-v${portablePythonVersion}-build.0/python-headless-${portablePythonVersion}-linux-x86_64.zip";
+        hash = "";  # nix will tell you the correct hash on first build
+        stripRoot = false;
+      };
+
+      # ── Build Python with packages for compilation (pybind11, sip) ──
+      buildPython = pkgs.python313.withPackages (ps: with ps; [
+        pybind11
+        sip
+        psutil
+      ]);
+
+      # ── Build Fluorine from source ──
+      fluorine-unwrapped = pkgs.stdenv.mkDerivation {
+        pname = "fluorine-manager-unwrapped";
+        inherit version;
+
+        src = self;
+
+        nativeBuildInputs = with pkgs; [
+          cmake
+          ninja
+          pkg-config
+          patchelf
+          qt6.wrapQtAppsHook
+        ];
+
+        buildInputs = with pkgs; [
+          # Qt 6
+          qt6.qtbase
+          qt6.qtwebengine
+          qt6.qtwebsockets
+          qt6.qtsvg
+          qt6.qtwayland
+
+          # Boost
+          boost
+
+          # Python (build-time)
+          buildPython
+
+          # System libraries
+          sqlite
+          tinyxml2
+          spdlog
+          fuse3
+          lz4
+          zlib
+          zstd
+          bzip2
+          xz
+          openssl
+          curl
+          tomlplusplus
+          fontconfig
+          freetype
+
+          # libloot (built above)
+          libloot
+        ];
+
+        # Disable Rust FFI builds in cmake — we built them separately.
+        cmakeFlags = [
+          "-DCMAKE_BUILD_TYPE=RelWithDebInfo"
+          "-DPython_EXECUTABLE=${buildPython}/bin/python3"
+          "-Dpybind11_DIR=${buildPython}/lib/python${pythonVersion}/site-packages/pybind11/share/cmake/pybind11"
+          "-DBUILD_PLUGIN_PYTHON=ON"
+          "-DBUILD_NAK_FFI=OFF"
+          "-DBUILD_BSA_FFI=OFF"
+        ];
+
+        # Replicate the staging logic from docker/build-inner.sh.
+        installPhase = ''
+          runHook preInstall
+
+          local RUNDIR=src/src
+          local PY_MM="${pythonVersion}"
+
+          mkdir -p $out/opt/fluorine-manager/{plugins,dlls,lib,qt6plugins}
+
+          # ── Main binary + helpers ──
+          cp -f $RUNDIR/ModOrganizer $out/opt/fluorine-manager/ModOrganizer-core
+          [ -f libs/lootcli/src/lootcli ] && cp -f libs/lootcli/src/lootcli $out/opt/fluorine-manager/
+
+          # ── MO2 plugins (.so) ──
+          find libs -type f \( \
+            -name "libgame_*.so" -o \
+            -name "libinstaller_*.so" -o \
+            -name "libfomod_plus_*.so" -o \
+            -name "libpreview_*.so" -o \
+            -name "libdiagnose_*.so" -o \
+            -name "libcheck_*.so" -o \
+            -name "libtool_*.so" -o \
+            -name "libinieditor.so" -o \
+            -name "libinibakery.so" -o \
+            -name "libbsa_extractor.so" -o \
+            -name "libbsa_packer.so" -o \
+            -name "libproxy.so" \
+          \) -exec cp -f {} $out/opt/fluorine-manager/plugins/ \;
+
+          # Python plugin payload.
+          for f in libplugin_python.so lzokay.py winreg.py pyCfg.py \
+                   DDSPreview.py Form43Checker.py ScriptExtenderPluginChecker.py; do
+            [ -f "src/src/plugins/$f" ] && cp -f "src/src/plugins/$f" $out/opt/fluorine-manager/plugins/
+          done
+          for d in basic_games data libs dlls; do
+            [ -d "src/src/plugins/$d" ] && cp -a "src/src/plugins/$d" $out/opt/fluorine-manager/plugins/
+          done
+          rm -f $out/opt/fluorine-manager/plugins/FNIS*.py
+
+          # Source-tree Python plugins.
+          for f in ../src/plugins/*.py; do
+            [ -f "$f" ] && cp -f "$f" $out/opt/fluorine-manager/plugins/
+          done
+
+          # ── Stylesheets ──
+          [ -d src/src/stylesheets ] && cp -a src/src/stylesheets $out/opt/fluorine-manager/
+
+          # ── 7z runtime ──
+          [ -f src/src/dlls/7z.so ] && cp -f src/src/dlls/7z.so $out/opt/fluorine-manager/dlls/
+
+          # ── Project libraries ──
+          cp -f libs/uibase/src/libuibase.so $out/opt/fluorine-manager/lib/
+          cp -f libs/libbsarch/liblibbsarch.so $out/opt/fluorine-manager/lib/
+          cp -f libs/archive/src/libarchive.so $out/opt/fluorine-manager/lib/
+          cp -f libs/plugin_python/src/runner/librunner.so $out/opt/fluorine-manager/lib/
+
+          # ── Pre-built Rust FFI libraries ──
+          cp -f ${bsa-ffi}/lib/libbsa_ffi.so $out/opt/fluorine-manager/lib/
+          cp -f ${nak-ffi}/lib/libnak_ffi.so $out/opt/fluorine-manager/lib/
+
+          # ── libloot ──
+          cp -Lf ${libloot}/lib/libloot.so* $out/opt/fluorine-manager/lib/ 2>/dev/null || true
+
+          # ── Boost (from nix store) ──
+          for boost_lib in ${pkgs.boost}/lib/libboost_program_options.so* \
+                           ${pkgs.boost}/lib/libboost_thread.so*; do
+            [ -f "$boost_lib" ] && cp -Lf "$boost_lib" $out/opt/fluorine-manager/lib/
+          done
+
+          # ── Qt6 plugins ──
+          QT6_PLUGIN_DIR="${pkgs.qt6.qtbase}/lib/qt-6/plugins"
+          for plugin_type in platforms tls networkinformation styles \
+                            imageformats iconengines xcbglintegrations \
+                            egldeviceintegrations; do
+            [ -d "$QT6_PLUGIN_DIR/$plugin_type" ] && \
+              cp -a "$QT6_PLUGIN_DIR/$plugin_type" $out/opt/fluorine-manager/qt6plugins/
+          done
+          # Wayland plugins.
+          WAYLAND_PLUGIN_DIR="${pkgs.qt6.qtwayland}/lib/qt-6/plugins"
+          for plugin_type in wayland-shell-integration \
+                            wayland-decoration-client wayland-graphics-integration-client; do
+            [ -d "$WAYLAND_PLUGIN_DIR/$plugin_type" ] && \
+              cp -a "$WAYLAND_PLUGIN_DIR/$plugin_type" $out/opt/fluorine-manager/qt6plugins/
+          done
+          # SVG plugin.
+          SVG_PLUGIN_DIR="${pkgs.qt6.qtsvg}/lib/qt-6/plugins"
+          [ -d "$SVG_PLUGIN_DIR/imageformats" ] && \
+            cp -a "$SVG_PLUGIN_DIR/imageformats"/. $out/opt/fluorine-manager/qt6plugins/imageformats/
+
+          # ── Bundle shared library dependencies ──
+          SKIP_PATTERN="linux-vdso|ld-linux|libc\.so|libm\.so|libdl\.so|librt\.so|libpthread|libresolv|libnss|libgcc_s|libstdc\+\+"
+          SKIP_PATTERN="$SKIP_PATTERN|libGL\.so|libEGL|libGLX|libGLdispatch|libdrm|libvulkan|libX11|libxcb|libwayland|libxkbcommon"
+          SKIP_PATTERN="$SKIP_PATTERN|libpython"
+
+          collect_and_bundle() {
+            ldd "$1" 2>/dev/null | grep "=>" | awk '{print $3}' | grep "^/" | while read -r dep; do
+              dep_name="$(basename "$dep")"
+              echo "$dep_name" | grep -qE "$SKIP_PATTERN" && continue
+              [ -f "$out/opt/fluorine-manager/lib/$dep_name" ] && continue
+              cp -Lf "$dep" "$out/opt/fluorine-manager/lib/" 2>/dev/null || true
+            done
+          }
+          collect_and_bundle "$out/opt/fluorine-manager/ModOrganizer-core"
+          find "$out/opt/fluorine-manager/plugins" -name "*.so" -exec bash -c 'ldd "$1" 2>/dev/null | grep "=>" | awk "{print \$3}" | grep "^/" | while read dep; do
+            dep_name="$(basename "$dep")"
+            echo "$dep_name" | grep -qE "'"$SKIP_PATTERN"'" && continue
+            [ -f "'"$out"'/opt/fluorine-manager/lib/$dep_name" ] && continue
+            cp -Lf "$dep" "'"$out"'/opt/fluorine-manager/lib/" 2>/dev/null || true
+          done' _ {} \;
+          find "$out/opt/fluorine-manager/lib" -name "*.so*" -exec bash -c 'ldd "$1" 2>/dev/null | grep "=>" | awk "{print \$3}" | grep "^/" | while read dep; do
+            dep_name="$(basename "$dep")"
+            echo "$dep_name" | grep -qE "'"$SKIP_PATTERN"'" && continue
+            [ -f "'"$out"'/opt/fluorine-manager/lib/$dep_name" ] && continue
+            cp -Lf "$dep" "'"$out"'/opt/fluorine-manager/lib/" 2>/dev/null || true
+          done' _ {} \;
+          [ -f "$out/opt/fluorine-manager/lootcli" ] && collect_and_bundle "$out/opt/fluorine-manager/lootcli"
+          rm -f "$out/opt/fluorine-manager/lib"/libpython*.so* 2>/dev/null || true
+
+          # ── Portable Python runtime ──
+          PP_SRC=$(echo ${portable-python}/python-headless-*)
+          if [ ! -d "$PP_SRC" ]; then
+            PP_SRC="${portable-python}"
+          fi
+          cp -a "$PP_SRC" $out/opt/fluorine-manager/python
+          chmod -R u+w $out/opt/fluorine-manager/python
+
+          # Trim portable Python.
+          PP_STDLIB="$out/opt/fluorine-manager/python/lib/python$PY_MM"
+          rm -rf "$PP_STDLIB/test" "$PP_STDLIB/idlelib" "$PP_STDLIB/tkinter" \
+                 "$PP_STDLIB/turtledemo" "$out/opt/fluorine-manager/python/include" \
+                 "$out/opt/fluorine-manager/python/share" 2>/dev/null || true
+          find "$out/opt/fluorine-manager/python" -type d -name "__pycache__" -exec rm -rf {} + 2>/dev/null || true
+
+          # Patch portable Python SONAME.
+          PP_LIBPY="$out/opt/fluorine-manager/python/lib/libpython$PY_MM.so"
+          if [ -f "$PP_LIBPY" ]; then
+            CURRENT_SONAME="$(readelf -d "$PP_LIBPY" 2>/dev/null | grep SONAME | sed 's/.*\[//' | sed 's/\]//')"
+            if [ "$CURRENT_SONAME" = "libpython$PY_MM.so" ]; then
+              patchelf --set-soname "libpython$PY_MM.so.1.0" "$PP_LIBPY"
+              mv "$PP_LIBPY" "$PP_LIBPY.1.0"
+              ln -sf "libpython$PY_MM.so.1.0" "$PP_LIBPY"
+            fi
+            [ ! -e "$PP_LIBPY.1.0" ] && ln -sf "libpython$PY_MM.so" "$PP_LIBPY.1.0"
+          fi
+
+          # Bundle PyQt6 into portable Python site-packages.
+          PYSITE="$out/opt/fluorine-manager/python/lib/python$PY_MM/site-packages"
+          mkdir -p "$PYSITE"
+          for search_dir in ${pkgs.python313Packages.pyqt6}/lib/python${pythonVersion}/site-packages; do
+            if [ -d "$search_dir/PyQt6" ]; then
+              cp -a "$search_dir/PyQt6" "$PYSITE/"
+              [ -d "$search_dir/PyQt6_sip" ] && cp -a "$search_dir/PyQt6_sip" "$PYSITE/"
+              [ -d "$search_dir/sip" ] && cp -a "$search_dir/sip" "$PYSITE/"
+              break
+            fi
+          done
+
+          # Build-tree Python plugin payload.
+          [ -d src/src/python ] && cp -a src/src/python/. $out/opt/fluorine-manager/python/
+
+          # ── icoutils (for .exe icon extraction) ──
+          cp -f ${pkgs.icoutils}/bin/wrestool $out/opt/fluorine-manager/ 2>/dev/null || true
+          cp -f ${pkgs.icoutils}/bin/icotool $out/opt/fluorine-manager/ 2>/dev/null || true
+
+          # ── Strip binaries ──
+          strip --strip-unneeded $out/opt/fluorine-manager/ModOrganizer-core 2>/dev/null || true
+          find $out/opt/fluorine-manager/plugins -name "*.so" -exec strip --strip-unneeded {} \; 2>/dev/null || true
+          find $out/opt/fluorine-manager/lib -name "*.so" -exec strip --strip-unneeded {} \; 2>/dev/null || true
+          [ -f "$out/opt/fluorine-manager/lootcli" ] && strip --strip-unneeded "$out/opt/fluorine-manager/lootcli" 2>/dev/null || true
+
+          # ── Patch RPATH ──
+          patchelf --force-rpath --set-rpath '$ORIGIN/lib:$ORIGIN/python/lib' \
+            $out/opt/fluorine-manager/ModOrganizer-core
+          [ -f "$out/opt/fluorine-manager/lootcli" ] && \
+            patchelf --force-rpath --set-rpath '$ORIGIN/lib' $out/opt/fluorine-manager/lootcli
+          find $out/opt/fluorine-manager/plugins -name "*.so" \
+            -exec patchelf --force-rpath --set-rpath '$ORIGIN/../lib:$ORIGIN/../python/lib' {} \; 2>/dev/null || true
+          find $out/opt/fluorine-manager/lib -name "*.so" \
+            -exec patchelf --force-rpath --set-rpath '$ORIGIN:$ORIGIN/../python/lib' {} \; 2>/dev/null || true
+
+          # ── Launcher script ──
+          cat > $out/opt/fluorine-manager/fluorine-manager <<'LAUNCH'
+#!/usr/bin/env bash
+set -euo pipefail
+SELF="$(readlink -f "$0")"
+HERE="$(cd "$(dirname "$SELF")" && pwd)"
+export PATH="${HERE}:${PATH}"
+
+export FLUORINE_ORIG_LD_LIBRARY_PATH="${LD_LIBRARY_PATH:-}"
+export FLUORINE_ORIG_PATH="${PATH}"
+export FLUORINE_ORIG_XDG_DATA_DIRS="${XDG_DATA_DIRS:-/usr/local/share:/usr/share}"
+export FLUORINE_ORIG_QT_PLUGIN_PATH="${QT_PLUGIN_PATH:-}"
+
+FLUORINE_DATA="${HOME}/.local/share/fluorine"
+PYTHON_DST="${FLUORINE_DATA}/python"
+PYTHON_SRC="${HERE}/python"
+
+if [ -d "${PYTHON_SRC}" ]; then
+  CURRENT_VER="$(stat -c '%i:%Y' "${PYTHON_SRC}/bin/python3" 2>/dev/null || echo "unknown")"
+  MARKER="${PYTHON_DST}/.version"
+  if [ ! -f "${MARKER}" ] || [ "$(cat "${MARKER}" 2>/dev/null)" != "${CURRENT_VER}" ]; then
+    echo "Syncing Python runtime to ${PYTHON_DST}..." >&2
+    rm -rf "${PYTHON_DST}"
+    mkdir -p "${PYTHON_DST}"
+    (cd "${PYTHON_SRC}" && tar --exclude-vcs -cf - .) | (cd "${PYTHON_DST}" && tar -xf -)
+    echo "${CURRENT_VER}" > "${MARKER}"
+  fi
+fi
+
+export LD_LIBRARY_PATH="${HERE}/lib:${PYTHON_DST}/lib:${LD_LIBRARY_PATH:-}"
+export MO2_BASE_DIR="${HERE}"
+export MO2_PLUGINS_DIR="${HERE}/plugins"
+export MO2_DLLS_DIR="${HERE}/dlls"
+export MO2_PYTHON_DIR="${PYTHON_DST}"
+MO2_PYTHONHOME="${PYTHON_DST}"
+unset PYTHONPATH PYTHONNOUSERSITE PYTHONHOME
+
+export QT_PLUGIN_PATH="${HERE}/qt6plugins"
+
+cd "${HERE}"
+exec env PYTHONHOME="${MO2_PYTHONHOME}" "${HERE}/ModOrganizer-core" "$@"
+LAUNCH
+          chmod +x $out/opt/fluorine-manager/fluorine-manager
+
+          # ── Desktop integration files ──
+          cp -f ../data/com.fluorine.manager.desktop $out/opt/fluorine-manager/ 2>/dev/null || true
+          cp -f ../data/com.fluorine.manager.png $out/opt/fluorine-manager/ 2>/dev/null || true
+          cp -f ../data/com.fluorine.manager.metainfo.xml $out/opt/fluorine-manager/ 2>/dev/null || true
+
+          mkdir -p $out/share/icons/hicolor/256x256/apps
+          mkdir -p $out/share/metainfo
+          cp $out/opt/fluorine-manager/com.fluorine.manager.png \
+             $out/share/icons/hicolor/256x256/apps/ 2>/dev/null || true
+          cp $out/opt/fluorine-manager/com.fluorine.manager.metainfo.xml \
+             $out/share/metainfo/ 2>/dev/null || true
+
+          runHook postInstall
+        '';
+      };
+
+      desktopItem = pkgs.makeDesktopItem {
+        name = "com.fluorine.manager";
+        exec = "fluorine-manager";
+        icon = "com.fluorine.manager";
+        desktopName = "Fluorine Manager";
+        genericName = "Mod Manager";
+        comment = "Mod Organizer 2 for Linux — manage your game mods";
+        categories = [ "Game" "Utility" ];
+        mimeTypes = [ "x-scheme-handler/nxm" ];
+        startupWMClass = "ModOrganizer";
+        keywords = [ "mod" "organizer" "modding" "skyrim" "fallout" ];
+      };
+
+      # ── FHS wrapper ──
+      fluorine-manager = pkgs.buildFHSEnv {
+        pname = "fluorine-manager";
+        inherit version;
+
+        runScript = "${fluorine-unwrapped}/opt/fluorine-manager/fluorine-manager";
+
+        targetPkgs = pkgs: with pkgs; [
+          glibc
+          stdenv.cc.cc.lib
+
+          libGL
+          libglvnd
+          libdrm
+          vulkan-loader
+          mesa
+
+          xorg.libX11
+          xorg.libxcb
+          xorg.libXext
+          xorg.libXrandr
+          xorg.libXcursor
+          xorg.libXi
+          xorg.libXfixes
+          xorg.libXrender
+          xorg.libXcomposite
+          xorg.libXdamage
+          xorg.libXtst
+          xorg.libXScrnSaver
+          xorg.libXinerama
+          libxkbcommon
+
+          wayland
+
+          fuse3
+
+          fontconfig
+          freetype
+
+          nss
+          nspr
+
+          zlib
+          dbus
+          glib
+          udev
+          libcap
+          polkit
+        ];
+
+        multiPkgs = pkgs: with pkgs; [
+          glibc
+          libGL
+          libglvnd
+          vulkan-loader
+          libdrm
+          udev
+          alsa-lib
+          libpulseaudio
+          dbus
+          freetype
+          fontconfig
+          zlib
+          glib
+          xorg.libX11
+          xorg.libxcb
+          xorg.libXext
+          xorg.libXrandr
+          xorg.libXcursor
+          xorg.libXi
+          xorg.libXfixes
+          xorg.libXrender
+          xorg.libXcomposite
+          xorg.libXdamage
+          xorg.libXtst
+          xorg.libXinerama
+          wayland
+          libxkbcommon
+          gnutls
+          SDL2
+          ncurses
+          cups
+        ];
+
+        multiArch = true;
+
+        unshareIpc = false;
+        unsharePid = false;
+
+        extraInstallCommands = ''
+          mkdir -p $out/share
+          ln -s ${desktopItem}/share/applications $out/share/applications
+          ln -s ${fluorine-unwrapped}/share/icons $out/share/icons
+          ln -s ${fluorine-unwrapped}/share/metainfo $out/share/metainfo
+        '';
+
+        meta = with pkgs.lib; {
+          description = "Mod Organizer 2 for Linux";
+          homepage = "https://github.com/SulfurNitride/Fluorine-Manager";
+          license = licenses.gpl3;
+          platforms = [ "x86_64-linux" ];
+          mainProgram = "fluorine-manager";
+        };
+      };
+
+    in {
+      packages.${system} = {
+        default = fluorine-manager;
+        inherit fluorine-manager fluorine-unwrapped libloot bsa-ffi nak-ffi;
+      };
+
+      apps.${system}.default = {
+        type = "app";
+        program = "${fluorine-manager}/bin/fluorine-manager";
+      };
+
+      # NixOS module for system-wide installation.
+      nixosModules.default = { config, lib, ... }: {
+        options.programs.fluorine-manager = {
+          enable = lib.mkEnableOption "Fluorine Manager (Mod Organizer 2 for Linux)";
+
+          fusePassthrough = lib.mkOption {
+            type = lib.types.bool;
+            default = false;
+            description = ''
+              Enable FUSE passthrough (kernel-direct I/O for mod files).
+              Grants CAP_SYS_ADMIN to the Fluorine binary via a
+              security wrapper.  Requires kernel 6.9+.
+            '';
+          };
+        };
+
+        config = lib.mkIf config.programs.fluorine-manager.enable {
+          environment.systemPackages = [ self.packages.${system}.default ];
+
+          programs.fuse.userAllowOther = true;
+
+          security.wrappers = lib.mkIf config.programs.fluorine-manager.fusePassthrough {
+            fluorine-manager = {
+              source = "${self.packages.${system}.default}/bin/fluorine-manager";
+              capabilities = "cap_sys_admin+ep";
+              owner = "root";
+              group = "root";
+            };
+          };
+        };
+      };
+    };
+}