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, 254 insertions, 0 deletions

diff --git a/libs/installer_bsplugins/src/MOPlugin/Settings.cpp b/libs/installer_bsplugins/src/MOPlugin/Settings.cpp
new file mode 100644
index 0000000..8ca77ec
--- /dev/null
+++ b/libs/installer_bsplugins/src/MOPlugin/Settings.cpp
@@ -0,0 +1,254 @@
+#include "Settings.h"
+#include "BSPlugins.h"
+
+#include <QDir>
+#include <QStandardPaths>
+#include <QTreeView>
+
+Settings* Instance = nullptr;
+
+static QString findIniPath(MOBase::IOrganizer* organizer)
+{
+  // FIXME: we can't find non-portable instance paths
+  return QDir(organizer->basePath()).filePath("ModOrganizer.ini");
+}
+
+Settings::Settings(MOBase::IOrganizer* organizer)
+    : Organizer{organizer}, MOSettings{findIniPath(organizer), QSettings::IniFormat}
+{
+  organizer->onPluginSettingChanged(
+      std::bind_front(&Settings::onPluginSettingChanged, this));
+}
+
+void Settings::init(MOBase::IOrganizer* organizer)
+{
+  Instance = new Settings(organizer);
+}
+
+Settings* Settings::instance()
+{
+  return Instance;
+}
+
+void Settings::set(const QString& setting, const QVariant& value)
+{
+  Organizer->setPersistent(BSPlugins::NAME, setting, value);
+}
+
+[[nodiscard]] QVariant Settings::get(const QString& setting, const QVariant& def) const
+{
+  return Organizer->persistent(BSPlugins::NAME, setting, def);
+}
+
+bool Settings::onSettingChanged(
+    const std::function<void(const QString&, const QVariant&, const QVariant&)>& func)
+{
+  auto connection = SettingChanged.connect(func);
+  return connection.connected();
+}
+
+QColor Settings::overwrittenLooseFilesColor() const
+{
+  return MOSettings.value("Settings/overwrittenLooseFilesColor", QColor(0, 255, 0, 64))
+      .value<QColor>();
+}
+
+QColor Settings::overwritingLooseFilesColor() const
+{
+  return MOSettings.value("Settings/overwritingLooseFilesColor", QColor(255, 0, 0, 64))
+      .value<QColor>();
+}
+
+QColor Settings::overwrittenArchiveFilesColor() const
+{
+  return MOSettings
+      .value("Settings/overwrittenArchiveFilesColor", QColor(0, 255, 255, 64))
+      .value<QColor>();
+}
+
+QColor Settings::overwritingArchiveFilesColor() const
+{
+  return MOSettings
+      .value("Settings/overwritingArchiveFilesColor", QColor(255, 0, 255, 64))
+      .value<QColor>();
+}
+
+QColor Settings::containedColor() const
+{
+  return MOSettings.value("Settings/containedColor", QColor(0, 0, 255, 64))
+      .value<QColor>();
+}
+
+bool Settings::offlineMode() const
+{
+  return MOSettings.value("Settings/offline_mode", false).value<bool>();
+}
+
+lootcli::LogLevels Settings::lootLogLevel() const
+{
+  // LOOT integration removed for Fluorine port — return default.
+  return lootcli::LogLevels::Info;
+}
+
+bool Settings::externalChangeWarning() const
+{
+  return Organizer->pluginSetting(BSPlugins::NAME, "external_change_warning")
+      .value<bool>();
+}
+
+bool Settings::enableSortButton() const
+{
+  return Organizer->pluginSetting(BSPlugins::NAME, "enable_sort_button").value<bool>();
+}
+
+bool Settings::lootShowDirty() const
+{
+  return Organizer->pluginSetting(BSPlugins::NAME, "loot_show_dirty").value<bool>();
+}
+
+bool Settings::lootShowMessages() const
+{
+  return Organizer->pluginSetting(BSPlugins::NAME, "loot_show_messages").value<bool>();
+}
+
+bool Settings::lootShowProblems() const
+{
+  return Organizer->pluginSetting(BSPlugins::NAME, "loot_show_problems").value<bool>();
+}
+
+static QString stateSettingName(const QHeaderView* header)
+{
+  return header->parent()->objectName() + "_header";
+}
+
+static void visitRows(const QAbstractItemModel* model,
+                      std::function<void(const QModelIndex&)> visit,
+                      const QModelIndex& root = QModelIndex())
+{
+  if (root.isValid()) {
+    visit(root);
+  }
+
+  for (int i = 0, count = model->rowCount(root); i < count; ++i) {
+    const auto idx = model->index(i, 0, root);
+    visitRows(model, visit, idx);
+  }
+}
+
+void Settings::saveTreeExpandState(const QTreeView* view)
+{
+  QVariantList expanded;
+  visitRows(view->model(), [&expanded, view](const QModelIndex& index) {
+    if (view->isExpanded(index)) {
+      expanded.append(index.data());
+    }
+  });
+
+  Organizer->setPersistent(BSPlugins::NAME, view->objectName() + "_expanded", expanded);
+}
+
+void Settings::restoreTreeExpandState(QTreeView* view) const
+{
+  // empty is serialized as invalid
+  const QVariant state = Organizer->persistent(
+      BSPlugins::NAME, view->objectName() + "_expanded", QVariantList());
+
+  if (!state.isValid()) {
+    view->collapseAll();
+  } else {
+    const auto expanded = state.toList();
+    if (!expanded.isEmpty()) {
+      view->collapseAll();
+      visitRows(view->model(), [&expanded, view](const QModelIndex& index) {
+        if (expanded.contains(index.data())) {
+          view->expand(index);
+        }
+      });
+    }
+  }
+}
+
+void Settings::saveState(const QHeaderView* header)
+{
+  Organizer->setPersistent(BSPlugins::NAME, stateSettingName(header),
+                           header->saveState());
+}
+
+void Settings::restoreState(QHeaderView* header) const
+{
+  const auto state =
+      Organizer->persistent(BSPlugins::NAME, stateSettingName(header)).toByteArray();
+  if (!state.isEmpty()) {
+    header->restoreState(state);
+  }
+}
+
+static QString stateSettingName(const QSplitter* splitter)
+{
+  return splitter->parentWidget()->objectName() + "_splitter";
+}
+
+void Settings::saveState(const QSplitter* splitter)
+{
+  Organizer->setPersistent(BSPlugins::NAME, stateSettingName(splitter),
+                           splitter->saveState());
+}
+
+void Settings::restoreState(QSplitter* splitter) const
+{
+  const auto state =
+      Organizer->persistent(BSPlugins::NAME, stateSettingName(splitter)).toByteArray();
+  if (!state.isEmpty()) {
+    splitter->restoreState(state);
+  }
+}
+
+static QString stateSettingName(const MOBase::ExpanderWidget* expander)
+{
+  return expander->button()->objectName() + "_state";
+}
+
+void Settings::saveState(const MOBase::ExpanderWidget* expander)
+{
+  Organizer->setPersistent(BSPlugins::NAME, stateSettingName(expander),
+                           expander->saveState());
+}
+
+void Settings::restoreState(MOBase::ExpanderWidget* expander) const
+{
+  const auto state =
+      Organizer->persistent(BSPlugins::NAME, stateSettingName(expander)).toByteArray();
+  if (!state.isEmpty()) {
+    expander->restoreState(state);
+  }
+}
+
+static QString geometrySettingName(const QDialog* dialog)
+{
+  return dialog->objectName() + "_geometry";
+}
+
+void Settings::saveGeometry(const QDialog* dialog)
+{
+  Organizer->setPersistent(BSPlugins::NAME, geometrySettingName(dialog),
+                           dialog->saveGeometry());
+}
+
+void Settings::restoreGeometry(QDialog* dialog) const
+{
+  const auto geometry =
+      Organizer->persistent(BSPlugins::NAME, geometrySettingName(dialog)).toByteArray();
+  if (!geometry.isEmpty()) {
+    dialog->restoreGeometry(geometry);
+  }
+}
+
+void Settings::onPluginSettingChanged(const QString& pluginName, const QString& key,
+                                      const QVariant& oldValue,
+                                      const QVariant& newValue)
+{
+  if (pluginName != BSPlugins::NAME)
+    return;
+
+  SettingChanged(key, oldValue, newValue);
+}