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, 291 insertions, 0 deletions

diff --git a/libs/installer_bsplugins/src/TESFile/Stream.h b/libs/installer_bsplugins/src/TESFile/Stream.h
new file mode 100644
index 0000000..db22580
--- /dev/null
+++ b/libs/installer_bsplugins/src/TESFile/Stream.h
@@ -0,0 +1,291 @@
+#ifndef TESFILE_STREAM_H
+#define TESFILE_STREAM_H
+
+#include "Type.h"
+
+#include <algorithm>
+#include <cctype>
+#include <cstdint>
+#include <cstring>
+#include <istream>
+#include <ranges>
+#include <utility>
+
+namespace TESFile
+{
+
+template <typename T>
+inline T readType(std::istream& stream)
+{
+  union
+  {
+    char buffer[sizeof(T)];
+    T value;
+  };
+  std::memset(buffer, 0x42, sizeof(T));
+  stream.read(buffer, sizeof(T));
+  return value;
+}
+
+inline std::string readZstring(std::istream& stream)
+{
+  std::string value;
+  std::getline(stream, value, '\0');
+  return value;
+}
+
+inline int icompare(const std::string& a, const std::string& b)
+{
+  const std::size_t n = std::min(a.size(), b.size());
+  for (std::size_t i = 0; i < n; ++i) {
+    const unsigned char ca =
+        static_cast<unsigned char>(std::tolower(static_cast<unsigned char>(a[i])));
+    const unsigned char cb =
+        static_cast<unsigned char>(std::tolower(static_cast<unsigned char>(b[i])));
+    if (ca != cb)
+      return ca < cb ? -1 : 1;
+  }
+  if (a.size() == b.size())
+    return 0;
+  return a.size() < b.size() ? -1 : 1;
+}
+
+inline bool iequals(const std::string& a, const std::string& b)
+{
+  return icompare(a, b) == 0;
+}
+
+template <std::ranges::input_range R, typename Proj = std::identity>
+inline auto find(R&& r, const std::string& value, Proj proj = {})
+{
+  return std::ranges::find_if(
+      r,
+      [&](auto&& val) {
+        return iequals(val, value);
+      },
+      proj);
+}
+
+struct less
+{
+  bool operator()(const std::string& a, const std::string& b) const
+  {
+    return icompare(a, b) < 0;
+  }
+};
+
+enum class TESFormat
+{
+  Standard,
+  Oblivion,
+  Morrowind,
+};
+
+enum class GroupType : std::int32_t
+{
+  Top,
+  WorldChildren,
+  InteriorCellBlock,
+  InteriorCellSubBlock,
+  ExteriorCellBlock,
+  ExteriorCellSubBlock,
+  CellChildren,
+  TopicChildren,
+  CellPersistentChildren,
+  CellTemporaryChildren,
+  QuestChildren,
+  CellVisibleDistantChildren = 10,
+};
+
+struct RecordFlags
+{
+  enum TES4Flag : std::uint32_t
+  {
+    Master    = 0x1,
+    Optimized = 0x10,
+    Localized = 0x80,
+    SmallNew  = 0x100,
+    SmallOld  = 0x200,
+    Update    = 0x200,
+    Medium    = 0x400,
+    Blueprint = 0x800,
+  };
+
+  enum Flag : std::uint32_t
+  {
+    Compressed = 0x40000,
+  };
+};
+
+struct RecordHeader
+{
+  Type type;
+  std::uint32_t dataSize;
+  union
+  {
+    struct
+    {
+      std::uint32_t flags;
+      std::uint32_t formId;
+    } formData;
+    struct
+    {
+      std::uint32_t label;
+      GroupType groupType;
+    } groupData;
+  };
+  union
+  {
+    struct
+    {
+      std::uint32_t revision;
+      Type firstChunk;
+    } old;
+    struct
+    {
+      std::uint16_t timestamp;
+      std::uint16_t revision;
+      std::uint16_t version;
+      std::uint16_t unknown1;
+    };
+  };
+};
+static_assert(sizeof(RecordHeader) == 24);
+
+struct ChunkHeader
+{
+  Type type;
+  std::uint16_t dataSize;
+};
+static_assert(sizeof(ChunkHeader) == 6);
+
+class GroupData final
+{
+public:
+  constexpr GroupData() : formId_{0}, groupType_{GroupType::Top} {}
+
+  constexpr GroupData(std::uint32_t label, GroupType type)
+      : formId_{label}, groupType_{type}
+  {}
+
+  constexpr auto operator<=>(const GroupData& other) const
+  {
+    if (groupType_ != other.groupType_) {
+      return groupType_ <=> other.groupType_;
+    } else {
+      if (hasFormType()) {
+        return formType() <=> other.formType();
+      } else if (hasBlock()) {
+        return block() <=> other.block();
+      } else if (hasGridCell()) {
+        return gridCell() <=> other.gridCell();
+      } else {
+        return formId_ <=> other.formId_;
+      }
+    }
+  }
+
+  constexpr bool operator==(const GroupData& other) const
+  {
+    return groupType_ == other.groupType_ && formId_ == other.formId_;
+  }
+
+  [[nodiscard]] constexpr GroupType type() const { return groupType_; }
+
+  [[nodiscard]] constexpr bool hasFormType() const
+  {
+    return groupType_ == GroupType::Top;
+  }
+
+  [[nodiscard]] constexpr bool hasParent() const
+  {
+    return groupType_ == GroupType::WorldChildren ||
+           groupType_ == GroupType::CellChildren ||
+           groupType_ == GroupType::TopicChildren ||
+           groupType_ == GroupType::CellPersistentChildren ||
+           groupType_ == GroupType::CellTemporaryChildren ||
+           groupType_ == GroupType::QuestChildren;
+  }
+
+  [[nodiscard]] constexpr bool hasDirectParent() const
+  {
+    return groupType_ == GroupType::WorldChildren ||
+           groupType_ == GroupType::CellChildren ||
+           groupType_ == GroupType::TopicChildren ||
+           groupType_ == GroupType::QuestChildren;
+  }
+
+  [[nodiscard]] constexpr bool hasBlock() const
+  {
+    return groupType_ == GroupType::InteriorCellBlock ||
+           groupType_ == GroupType::InteriorCellSubBlock;
+  }
+
+  [[nodiscard]] constexpr bool hasGridCell() const
+  {
+    return groupType_ == GroupType::ExteriorCellBlock ||
+           groupType_ == GroupType::ExteriorCellSubBlock;
+  }
+
+  [[nodiscard]] constexpr Type formType() const { return formType_; }
+
+  [[nodiscard]] constexpr std::uint32_t parent() const { return formId_; }
+
+  [[nodiscard]] constexpr std::int32_t block() const { return number_; }
+
+  [[nodiscard]] constexpr std::pair<std::int16_t, std::int16_t> gridCell() const
+  {
+    return {cell_.x, cell_.y};
+  }
+
+  constexpr void setLocalIndex(std::uint8_t index)
+  {
+    if (hasParent()) {
+      formId_ = (formId_ & 0xFFFFFFU) | (index << 24U);
+    }
+  }
+
+private:
+  GroupType groupType_;
+  union
+  {
+    Type formType_;
+    std::uint32_t formId_;
+    std::int32_t number_;
+    struct
+    {
+      std::int16_t y;
+      std::int16_t x;
+    } cell_;
+  };
+};
+
+class FormData final
+{
+public:
+  constexpr FormData(Type type, std::uint32_t flags, std::uint32_t formId, std::uint16_t formVersion)
+      : type_{type}, flags_{flags}, formId_{formId}, formVersion_{formVersion}
+  {}
+
+  [[nodiscard]] constexpr Type type() const { return type_; }
+
+  [[nodiscard]] constexpr std::uint32_t flags() const { return flags_; }
+
+  [[nodiscard]] constexpr std::uint32_t formId() const { return formId_; }
+
+  [[nodiscard]] constexpr std::uint16_t formVersion() const { return formVersion_; }
+
+  [[nodiscard]] constexpr std::uint8_t localModIndex() const { return formId_ >> 24; }
+
+private:
+  Type type_;
+  std::uint32_t flags_;
+  std::uint32_t formId_;
+  std::uint16_t formVersion_;
+};
+
+}  // namespace TESFile
+
+using namespace TESFile::literals;
+
+#endif  // TESFILE_STREAM_H