Add BSA in-memory extraction and nested preview support

bsatk:
- Archive::extractToMemory() extracts a file directly into a byte buffer
  instead of a filesystem path, backed by a std::ostringstream sink.
- Archive::findFile() locates a file by relative path, case-insensitive
  and separator-agnostic, walking the folder tree recursively.
- extractDirect/extractCompressed now take std::ostream& so both the
  ofstream and ostringstream paths share the same implementation.

libbsarch: shim rewrite on Linux to map the Windows API surface onto
bsatk::Archive, enabling preview_bsa to open vanilla BSAs via the
same interface as other plugins.

preview_bsa: double-click on a file in the BSA tree now extracts the
bytes via extractToMemory() and hands them to IOrganizer::previewFileData
for nested preview rendering (e.g. NIF inside a BSA).

uibase + organizerproxy + organizercore: new IOrganizer::previewFileData
virtual that routes in-memory file bytes through the first registered
IPluginPreview matching the extension. Uses heap + WA_DeleteOnClose +
open() to avoid nested exec() softlock from mod info filetree ->
preview_bsa tree -> nif preview.

docker/build-inner.sh: stage preview_nif shaders into plugin_data/shaders
so ShaderManager can load them via IOrganizer::getPluginDataPath().

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

1 files changed, 14 insertions, 2 deletions

diff --git a/libs/libbsarch/CMakeLists.txt b/libs/libbsarch/CMakeLists.txt
index d3e994e..db92b91 100644
--- a/libs/libbsarch/CMakeLists.txt
+++ b/libs/libbsarch/CMakeLists.txt
@@ -29,12 +29,24 @@ else()
             BASE_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/include
             FILES ${CMAKE_CURRENT_SOURCE_DIR}/include/libbsarch/libbsarch.h
     )
-    # Set default symbol visibility to hidden, export only marked symbols
+    # Set default symbol visibility to hidden, export only marked symbols.
+    # libbsarch.cpp uses BSARCH_DLL_API which maps to
+    # __attribute__((visibility("default"))) when BSARCH_DLL_EXPORT is set,
+    # so the C API stays exported while the bsatk bridge stays internal.
     target_compile_options(libbsarch PRIVATE -fvisibility=hidden)
 endif()
 target_include_directories(libbsarch PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include/libbsarch)
-set_target_properties(libbsarch PROPERTIES DEBUG_POSTFIX "d" CXX_STANDARD 11)
+if(WIN32)
+    set_target_properties(libbsarch PROPERTIES DEBUG_POSTFIX "d" CXX_STANDARD 11)
+else()
+    # Linux impl is backed by bsatk and needs C++17 for std::string::data()
+    # non-const and the rest of the bsatk API.
+    set_target_properties(libbsarch PROPERTIES DEBUG_POSTFIX "d" CXX_STANDARD 17)
+endif()
 target_link_libraries(libbsarch PUBLIC mo2::dds-header)
+if(NOT WIN32)
+    target_link_libraries(libbsarch PRIVATE mo2::bsatk)
+endif()
 target_compile_definitions(libbsarch PRIVATE BSARCH_DLL_EXPORT)
 
 # preprocessor definitions