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, 227 insertions, 0 deletions

diff --git a/libs/installer_bsplugins/src/TESData/FileEntry.cpp b/libs/installer_bsplugins/src/TESData/FileEntry.cpp
new file mode 100644
index 0000000..4eb1e02
--- /dev/null
+++ b/libs/installer_bsplugins/src/TESData/FileEntry.cpp
@@ -0,0 +1,227 @@
+#include "FileEntry.h"
+
+#include <algorithm>
+#include <iterator>
+#include <mutex>
+#include <shared_mutex>
+#include <utility>
+
+namespace TESData
+{
+
+FileEntry::FileEntry(TESFileHandle handle, const std::string& name)
+    : m_Handle{handle}, m_Name{name}, m_Root{std::make_shared<TreeItem>()}
+{}
+
+void FileEntry::forEachRecord(
+    std::function<void(const std::shared_ptr<const Record>&)> func) const
+{
+  std::vector<std::shared_ptr<TreeItem>> stack;
+  stack.push_back(m_Root);
+  while (!stack.empty()) {
+    const auto item = std::move(stack.back());
+    stack.pop_back();
+
+    if (item->record) {
+      func(item->record);
+    }
+
+    for (const auto& [identifier, child] : item->children) {
+      stack.push_back(child);
+    }
+  }
+}
+
+std::shared_ptr<Record> FileEntry::createRecord(const RecordPath& path,
+                                                const std::string& name,
+                                                TESFile::Type formType)
+{
+  const auto item = createHierarchy(path);
+
+  std::unique_lock lk{m_Mutex};
+
+  if (!item->record) {
+    item->record = std::make_shared<Record>();
+    lk.unlock();
+
+    item->record->setIdentifier(path.identifier(), path.files());
+    item->record->addAlternative(m_Handle);
+    item->name     = name;
+    item->formType = formType;
+  }
+
+  return item->record;
+}
+
+void FileEntry::addRecord(const RecordPath& path, const std::string& name,
+                          TESFile::Type formType, std::shared_ptr<Record> record)
+{
+  record->addAlternative(m_Handle);
+  const auto item = createHierarchy(path);
+  item->record    = record;
+  item->name      = name;
+  item->formType  = formType;
+}
+
+void FileEntry::addChildGroup(const RecordPath& path)
+{
+  const auto item = findItem(path);
+  if (!item || !item->record) {
+    // no record to add children to
+    return;
+  }
+
+  TESFile::GroupData group = path.groups().back();
+  if (group.hasParent()) {
+    const auto& file            = path.files()[group.parent() >> 24];
+    const std::uint8_t newIndex = static_cast<std::uint8_t>(
+        std::distance(std::begin(m_Files), TESFile::find(m_Files, file)));
+
+    if (newIndex == m_Files.size()) {
+      m_Files.push_back(file);
+    }
+
+    group.setLocalIndex(newIndex);
+  }
+
+  item->group = group;
+}
+
+std::shared_ptr<Record> FileEntry::findRecord(const RecordPath& path) const
+{
+  const auto item = findItem(path);
+  return item ? item->record : nullptr;
+}
+
+std::shared_ptr<FileEntry::TreeItem> FileEntry::findItem(const RecordPath& path) const
+{
+  std::shared_lock lk{m_Mutex};
+
+  const auto groups = path.groups();
+  auto item         = m_Root;
+  for (TESFile::GroupData group : groups) {
+    if (group.hasParent()) {
+      const auto& file            = path.files()[group.parent() >> 24];
+      const std::uint8_t newIndex = static_cast<std::uint8_t>(
+          std::distance(std::begin(m_Files), TESFile::find(m_Files, file)));
+
+      if (newIndex == m_Files.size()) {
+        return nullptr;
+      }
+
+      group.setLocalIndex(newIndex);
+    }
+
+    if (group.hasDirectParent() &&
+        (!item->record || item->record->formId() != group.parent())) {
+      if (const auto it = item->children.find(group.parent());
+          it != item->children.end()) {
+        item = it->second;
+      } else {
+        return nullptr;
+      }
+    } else {
+      if (const auto it = item->children.find(group); it != item->children.end()) {
+        item = it->second;
+      } else {
+        return nullptr;
+      }
+    }
+  }
+
+  TreeItem::Key key;
+  if (path.hasFormId()) {
+    const auto& file            = path.files()[path.formId() >> 24];
+    const std::uint8_t newIndex = static_cast<std::uint8_t>(
+        std::distance(std::begin(m_Files), TESFile::find(m_Files, file)));
+
+    if (newIndex == m_Files.size()) {
+      return nullptr;
+    }
+
+    const std::uint32_t formId = (path.formId() & 0xFFFFFFU) | (newIndex << 24U);
+    key                        = formId;
+  } else if (path.hasEditorId()) {
+    key = path.editorId();
+  } else if (path.hasTypeId()) {
+    key = path.typeId();
+  } else {
+    return item;
+  }
+
+  const auto it = item->children.find(key);
+  return it != item->children.end() ? it->second : nullptr;
+}
+
+std::shared_ptr<FileEntry::TreeItem> FileEntry::createHierarchy(const RecordPath& path)
+{
+  std::unique_lock lk{m_Mutex};
+
+  const auto groups = path.groups();
+  auto item         = m_Root;
+  for (TESFile::GroupData group : groups) {
+    if (group.hasParent()) {
+      const auto& file            = path.files()[group.parent() >> 24];
+      const std::uint8_t newIndex = static_cast<std::uint8_t>(
+          std::distance(std::begin(m_Files), TESFile::find(m_Files, file)));
+
+      if (newIndex == m_Files.size()) {
+        m_Files.push_back(file);
+      }
+
+      group.setLocalIndex(newIndex);
+    }
+
+    if (group.hasDirectParent() &&
+        (!item->record || item->record->formId() != group.parent())) {
+      auto& nextItem = item->children[group.parent()];
+      if (!nextItem) {
+        nextItem         = std::make_shared<TreeItem>();
+        nextItem->parent = item.get();
+        nextItem->record = std::make_shared<Record>();
+        nextItem->record->setIdentifier(group.parent(), m_Files);
+      }
+      nextItem->group = group;
+
+      item = nextItem;
+    } else {
+      auto& nextItem = item->children[group];
+      if (!nextItem) {
+        nextItem         = std::make_shared<TreeItem>();
+        nextItem->parent = item.get();
+        nextItem->group  = group;
+      }
+      item = nextItem;
+    }
+  }
+
+  TreeItem::Key key;
+  if (path.hasFormId()) {
+    const auto& file            = path.files()[path.formId() >> 24];
+    const std::uint8_t newIndex = static_cast<std::uint8_t>(
+        std::distance(std::begin(m_Files), TESFile::find(m_Files, file)));
+
+    if (newIndex == m_Files.size()) {
+      m_Files.push_back(file);
+    }
+
+    const std::uint32_t formId = (path.formId() & 0xFFFFFFU) | (newIndex << 24U);
+    key                        = formId;
+  } else if (path.hasEditorId()) {
+    key = path.editorId();
+  } else if (path.hasTypeId()) {
+    key = path.typeId();
+  } else {
+    return item;
+  }
+
+  auto& recordItem = item->children[key];
+  if (!recordItem) {
+    recordItem         = std::make_shared<TreeItem>();
+    recordItem->parent = item.get();
+  }
+
+  return recordItem;
+}
+
+}  // namespace TESData