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, 7 insertions, 0 deletions

diff --git a/libs/preview_bsa/src/simplefiletreeitem.h b/libs/preview_bsa/src/simplefiletreeitem.h
index 3d5ddd7..b3a6eb4 100644
--- a/libs/preview_bsa/src/simplefiletreeitem.h
+++ b/libs/preview_bsa/src/simplefiletreeitem.h
@@ -1,6 +1,7 @@
 #ifndef SIMPLEFILETREEITEM_H
 #define SIMPLEFILETREEITEM_H
 
+#include <QString>
 #include <QVariant>
 #include <QVector>
 
@@ -22,6 +23,12 @@ public:
   int row() const;
   SimpleFileTreeItem* parentItem();
 
+  /**
+   * Walk up to the root, joining each ancestor's name with @p separator.
+   * Returns the archive-relative path of this item.
+   */
+  QString fullPath(QChar separator = QLatin1Char('/')) const;
+
 private:
   QVector<SimpleFileTreeItem*> m_childItems;
   QHash<QString, SimpleFileTreeItem*> m_childItemsByName;