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, 67 insertions, 0 deletions

diff --git a/libs/installer_bsplugins/src/BSPluginList/FlagIconDelegate.cpp b/libs/installer_bsplugins/src/BSPluginList/FlagIconDelegate.cpp
new file mode 100644
index 0000000..72be162
--- /dev/null
+++ b/libs/installer_bsplugins/src/BSPluginList/FlagIconDelegate.cpp
@@ -0,0 +1,67 @@
+#include "FlagIconDelegate.h"
+
+#include <bit>
+
+namespace BSPluginList
+{
+
+using enum TESData::FileInfo::EFlag;
+
+FlagIconDelegate::FlagIconDelegate(PluginListView* view)
+    : GUI::IconDelegate(view), m_View{view}
+{}
+
+QList<QString> FlagIconDelegate::getIcons(const QModelIndex& index) const
+{
+  const auto flags = m_View->fileFlags(index);
+
+  QList<QString> icons;
+
+  if (flags & FLAG_PROBLEMATIC) {
+    icons.append(":/MO/gui/warning");
+  }
+
+  if (flags & FLAG_INFORMATION) {
+    icons.append(":/MO/gui/information");
+  }
+
+  if (flags & FLAG_INI) {
+    icons.append(":/MO/gui/attachment");
+  }
+
+  if (flags & FLAG_BSA) {
+    icons.append(":/MO/gui/archive_conflict_neutral");
+  }
+
+  if (flags & FLAG_MASTER) {
+    icons.append(":/bsplugins/star");
+  }
+
+  if (flags & FLAG_LIGHT) {
+    icons.append(":/bsplugins/feather");
+  }
+
+  if (flags & FLAG_MEDIUM) {
+    icons.append(":/MO/gui/run");
+    if (flags & FLAG_LIGHT) {
+      icons.append(":/MO/gui/warning");
+    }
+  }
+
+  if (flags & FLAG_BLUEPRINT) {
+    icons.append(":/MO/gui/resources/go-down.png");
+  }
+
+  if (flags & FLAG_CLEAN) {
+    icons.append(":/MO/gui/edit_clear");
+  }
+
+  return icons;
+}
+
+int FlagIconDelegate::getNumIcons(const QModelIndex& index) const
+{
+  return std::popcount(static_cast<uint>(m_View->fileFlags(index)));
+}
+
+}  // namespace BSPluginList