Add FUSE external mapping support, BG3/Oblivion Remastered fixes, fomod-plus and NaK integration

FUSE VFS now deploys non-data-dir mod mappings (Paks, OBSE, UE4SS, etc.)
via real symlinks and injects file-level data-dir mappings (plugins.txt,
loadorder.txt) into the VFS tree. Fixes game launches for Oblivion
Remastered (Root Builder path resolution, script extender support) and
BG3 (Wine prefix documents directory, file mapper symlinks on Linux).

Vendors mo2-fomod-plus plugin and NaK crate for FOMOD installer and
game finder/runtime support.

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

1 files changed, 53 insertions, 0 deletions

diff --git a/libs/installer_fomod_plus/installer/CMakeLists.txt b/libs/installer_fomod_plus/installer/CMakeLists.txt
new file mode 100644
index 0000000..70018ff
--- /dev/null
+++ b/libs/installer_fomod_plus/installer/CMakeLists.txt
@@ -0,0 +1,53 @@
+cmake_minimum_required(VERSION 3.16)
+include(FetchContent)
+
+file(GLOB_RECURSE INSTALLER_SOURCES CONFIGURE_DEPENDS
+    ${CMAKE_CURRENT_SOURCE_DIR}/*.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/*.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/*.ui
+    ${CMAKE_CURRENT_SOURCE_DIR}/*.qrc
+)
+file(GLOB SHARE_SOURCES "${CMAKE_CURRENT_SOURCE_DIR}/../share/**/*.cpp")
+
+add_library(fomod_plus_installer SHARED ${INSTALLER_SOURCES} ${SHARE_SOURCES})
+
+target_include_directories(
+        fomod_plus_installer
+        PUBLIC
+        ${CMAKE_CURRENT_SOURCE_DIR}/../share
+        ${MO2_UIBASE_INCLUDE_DIRS}
+        ${MO2_ARCHIVE_INCLUDE_DIRS}
+        ${CMAKE_CURRENT_SOURCE_DIR}
+)
+
+FetchContent_Declare(
+        pugixml
+        GIT_REPOSITORY https://github.com/zeux/pugixml
+        GIT_TAG v1.14
+        PATCH_COMMAND ${CMAKE_COMMAND}
+                -DPUGIXML_CMAKELISTS=<SOURCE_DIR>/CMakeLists.txt
+                -P ${CMAKE_CURRENT_LIST_DIR}/../cmake/patch_pugixml.cmake
+)
+
+FetchContent_Declare(json URL https://github.com/nlohmann/json/releases/download/v3.11.3/json.tar.xz)
+FetchContent_MakeAvailable(pugixml json)
+
+set(project_type plugin)
+project(fomod_plus_installer)
+
+target_link_libraries(fomod_plus_installer PRIVATE mo2::uibase pugixml nlohmann_json::nlohmann_json)
+if (WIN32)
+    target_link_libraries(fomod_plus_installer PRIVATE dbghelp)
+endif ()
+mo2_configure_plugin(fomod_plus_installer NO_SOURCES WARNINGS OFF PRIVATE_DEPENDS)
+
+if (MSVC)
+    target_compile_options(fomod_plus_installer PRIVATE $<$<CONFIG:RelWithDebInfo>:/Zi>)
+    target_link_options(fomod_plus_installer PRIVATE $<$<CONFIG:RelWithDebInfo>:/DEBUG>)
+    install(FILES $<TARGET_PDB_FILE:fomod_plus_installer>
+            DESTINATION ${CMAKE_RUNTIME_OUTPUT_DIRECTORY_RELWITHDEBINFO}
+            CONFIGURATIONS RelWithDebInfo
+            OPTIONAL)
+endif ()
+
+mo2_install_target(fomod_plus_installer)