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, 86 insertions, 0 deletions

diff --git a/libs/installer_bsplugins/src/TESData/RecordPath.h b/libs/installer_bsplugins/src/TESData/RecordPath.h
new file mode 100644
index 0000000..712edfa
--- /dev/null
+++ b/libs/installer_bsplugins/src/TESData/RecordPath.h
@@ -0,0 +1,86 @@
+#ifndef TESDATA_RECORDPATH_H
+#define TESDATA_RECORDPATH_H
+
+#include "TESFile/Stream.h"
+
+#include <boost/container/small_vector.hpp>
+
+#include <cstdint>
+#include <span>
+#include <string>
+#include <variant>
+
+namespace TESData
+{
+
+class RecordPath final
+{
+public:
+  using Identifier =
+      std::variant<std::monostate, std::uint32_t, std::string, TESFile::Type>;
+
+  [[nodiscard]] bool hasFormId() const
+  {
+    return std::holds_alternative<std::uint32_t>(m_Identifier);
+  }
+
+  [[nodiscard]] bool hasEditorId() const
+  {
+    return std::holds_alternative<std::string>(m_Identifier);
+  }
+
+  [[nodiscard]] bool hasTypeId() const
+  {
+    return std::holds_alternative<TESFile::Type>(m_Identifier);
+  }
+
+  [[nodiscard]] std::uint32_t formId() const
+  {
+    return std::get<std::uint32_t>(m_Identifier);
+  }
+
+  [[nodiscard]] const std::string& editorId() const
+  {
+    return std::get<std::string>(m_Identifier);
+  }
+
+  [[nodiscard]] TESFile::Type typeId() const
+  {
+    return std::get<TESFile::Type>(m_Identifier);
+  }
+
+  [[nodiscard]] std::span<const std::string> files() const { return m_Files; }
+
+  [[nodiscard]] std::span<const TESFile::GroupData> groups() const { return m_Groups; }
+
+  [[nodiscard]] const auto& identifier() const { return m_Identifier; }
+
+  [[nodiscard]] std::string string() const;
+
+  void setFormId(std::uint32_t formId, std::span<const std::string> masters,
+                 const std::string& file);
+
+  void unsetFormId();
+
+  void setEditorId(const std::string& editorId);
+
+  void setTypeId(TESFile::Type type);
+
+  void setIdentifier(const Identifier& identifier, std::span<const std::string> files);
+
+  void push(TESFile::GroupData group, const std::span<const std::string> masters,
+            const std::string& file);
+
+  void pop();
+
+private:
+  void cleanLastFile();
+
+  boost::container::small_vector<std::string, 2> m_Files;
+  boost::container::small_vector<TESFile::GroupData, 4> m_Groups;
+  Identifier m_Identifier;
+};
+
+}  // namespace TESData
+
+#endif  // TESDATA_RECORDPATH_H