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, 119 insertions, 0 deletions

diff --git a/libs/installer_bsplugins/src/BSPluginList/PluginListStyledItemDelegate.cpp b/libs/installer_bsplugins/src/BSPluginList/PluginListStyledItemDelegate.cpp
new file mode 100644
index 0000000..141ef17
--- /dev/null
+++ b/libs/installer_bsplugins/src/BSPluginList/PluginListStyledItemDelegate.cpp
@@ -0,0 +1,119 @@
+#include "PluginListStyledItemDelegate.h"
+#include "PluginListModel.h"
+#include "PluginListView.h"
+
+#include <QApplication>
+
+namespace BSPluginList
+{
+
+PluginListStyledItemDelegate::PluginListStyledItemDelegate(PluginListView* view)
+    : QStyledItemDelegate(view), m_View{view}
+{}
+
+void PluginListStyledItemDelegate::paint(QPainter* painter,
+                                         const QStyleOptionViewItem& option,
+                                         const QModelIndex& index) const
+{
+  QStyleOptionViewItem opt(option);
+
+  if (index.column() == 0) {
+    if (!index.model()->hasChildren(index) || !index.data().isValid()) {
+      opt.rect.adjust(-m_View->indentation(), 0, 0, 0);
+    }
+  }
+
+  const auto color    = m_View->markerColor(index);
+  opt.backgroundBrush = color;
+
+  const auto widget = opt.widget;
+  const auto style  = widget ? widget->style() : QApplication::style();
+
+  if (!index.siblingAtColumn(0).data().isValid()) {
+    QStyleOptionFrame optFrame;
+    optFrame.initFrom(widget);
+    optFrame.rect         = opt.rect;
+    optFrame.frameShape   = QFrame::HLine;
+    optFrame.lineWidth    = 0;
+    optFrame.midLineWidth = 1;
+    optFrame.state |= QStyle::State_Sunken;
+
+    QApplication::style()->drawControl(QStyle::CE_ShapedFrame, &optFrame, painter,
+                                       widget);
+    return;
+  }
+
+  const auto plugin =
+      index.data(PluginListModel::InfoRole).value<const TESData::FileInfo*>();
+
+  bool disabledText = false;
+  switch (index.column()) {
+  case PluginListModel::COL_NAME:
+    disabledText = plugin && plugin->isAlwaysEnabled();
+    break;
+  case PluginListModel::COL_PRIORITY:
+  case PluginListModel::COL_MODINDEX:
+    disabledText = plugin && plugin->forceLoaded();
+    break;
+  }
+
+  if (disabledText) {
+    opt.palette.setBrush(QPalette::Text,
+                         opt.palette.brush(QPalette::Disabled, QPalette::Text));
+  }
+
+  // HACK: we can't normally have a disabled checkbox on a selectable row, so create a
+  // margin for it and then draw one manually
+  bool drawCheck = false;
+  bool enabled   = false;
+  if (index.column() == 0 && !index.data(Qt::CheckStateRole).isValid()) {
+    if (plugin) {
+      drawCheck = true;
+      if (plugin->forceLoaded() || plugin->forceEnabled()) {
+        enabled = true;
+      }
+    }
+
+    // set decoration size to use as text margin
+    opt.decorationSize.setWidth(
+        style->pixelMetric(QStyle::PM_IndicatorWidth, &opt, widget));
+  }
+
+  QStyledItemDelegate::paint(painter, opt, index);
+
+  // draw check on top
+  if (drawCheck) {
+    opt.features |= QStyleOptionViewItem::HasCheckIndicator;
+
+    QRect checkRect =
+        style->subElementRect(QStyle::SE_ItemViewItemCheckIndicator, &opt, widget);
+    opt.rect = checkRect;
+
+    opt.state &= ~QStyle::State_Enabled;
+    if (enabled) {
+      opt.state |= QStyle::State_On;
+    }
+
+    style->drawPrimitive(QStyle::PE_IndicatorItemViewItemCheck, &opt, painter, widget);
+  }
+}
+
+void PluginListStyledItemDelegate::initStyleOption(QStyleOptionViewItem* option,
+                                                   const QModelIndex& index) const
+{
+  const auto backgroundColor = option->backgroundBrush.color();
+  QStyledItemDelegate::initStyleOption(option, index);
+
+  // HACK: create a text margin where the checkbox should be
+  if (index.column() == 0 && !index.data(Qt::CheckStateRole).isValid()) {
+    if (index.data(PluginListModel::InfoRole).isValid()) {
+      option->features |= QStyleOptionViewItem::HasDecoration;
+    }
+  }
+
+  if (backgroundColor.isValid()) {
+    option->backgroundBrush = backgroundColor;
+  }
+}
+
+}  // namespace BSPluginList