VFS perf fixes, icon/stylesheet compat, download filename fix

VFS:
- Open backing fd at mo2_open time for read-only handles so mo2_read can
  splice without re-opening the file on every read call.
- Bump RLIMIT_NOFILE at mount time to fit the resulting fd pressure when
  the game keeps hundreds of BSAs open.
- Dedicated node_cache_mutex so resolveByInode / mo2_lookup stop racing
  unordered_map writes while multiple tree_mutex readers are active.
- max_read=1MB + matching conn->max_read and raised max_readahead/max_write
  so the kernel merges Wine's small sequential reads into bigger FUSE
  requests.
- Per-op wall-clock counters in mo2_init() logs so we can distinguish VFS
  latency from game-side work.

Proton launch:
- Write dxvk.conf to the prefix and set DXVK_CONFIG_FILE to force
  dxvk.enableGraphicsPipelineLibrary=False, avoiding long GPL compile
  stalls on first run.

UI / plugin compat:
- Clamp IconDelegate's per-icon width to [8, 16] so narrow content
  columns don't trigger QIcon::pixmap(0,0) returning null and logging
  "failed to load icon" every repaint.
- Pre-create lowercase symlinks in the stylesheet directory so QSS files
  authored on Windows resolve url(foo.svg) when on-disk files are Foo.svg.
- Flip content icons empty-chessboard.png and facegen.png to 8-bit RGBA
  so Qt's built-in PNG reader loads them uniformly.
- Add mobase.Version.canonicalString shim for legacy Python plugins that
  still call the old VersionInfo method on appVersion()'s return.
- BSPluginList: compare normalized plugin name lists instead of byte
  hashes so the post-run case-fix refresh stops spuriously firing the
  "load order changed" dialog.
- BSPluginList disabled by default.

Download manager:
- Parse CDN URL with QUrl + QUrlQuery and read the filename from the
  response-content-disposition query param (RFC 6266 quoted / unquoted /
  ext-value forms), not QFileInfo on the raw URL.
- When the API or URL gives us a CDN object key (no archive extension),
  prefer the actual Content-Disposition header from the live response in
  metaDataChanged and downloadFinished.

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

1 files changed, 37 insertions, 0 deletions

diff --git a/libs/installer_bsplugins/src/BSPluginInfo/AuxTreeModel.h b/libs/installer_bsplugins/src/BSPluginInfo/AuxTreeModel.h
new file mode 100644
index 0000000..6663aa8
--- /dev/null
+++ b/libs/installer_bsplugins/src/BSPluginInfo/AuxTreeModel.h
@@ -0,0 +1,37 @@
+#ifndef BSPLUGININFO_AUXTREEMODEL_H
+#define BSPLUGININFO_AUXTREEMODEL_H
+
+#include "TESData/AssociatedEntry.h"
+
+#include <QAbstractItemModel>
+
+namespace BSPluginInfo
+{
+
+class AuxTreeModel final : public QAbstractItemModel
+{
+  Q_OBJECT
+
+public:
+  explicit AuxTreeModel(const TESData::AssociatedEntry* entry,
+                        QObject* parent = nullptr);
+
+  QModelIndex index(int row, int column,
+                    const QModelIndex& parent = QModelIndex()) const override;
+  QModelIndex parent(const QModelIndex& index) const override;
+  int rowCount(const QModelIndex& parent = QModelIndex()) const override;
+  int columnCount(const QModelIndex& parent = QModelIndex()) const override;
+
+  QVariant data(const QModelIndex& index, int role = Qt::DisplayRole) const override;
+  QVariant headerData(int section, Qt::Orientation orientation,
+                      int role = Qt::DisplayRole) const override;
+
+private:
+  using Item = TESData::AuxItem;
+
+  const TESData::AssociatedEntry* m_Entry;
+};
+
+}  // namespace BSPluginInfo
+
+#endif  // BSPLUGININFO_AUXTREEMODEL_H