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, 90 insertions, 0 deletions

diff --git a/libs/installer_bsplugins/src/TESData/Record.h b/libs/installer_bsplugins/src/TESData/Record.h
new file mode 100644
index 0000000..0edda85
--- /dev/null
+++ b/libs/installer_bsplugins/src/TESData/Record.h
@@ -0,0 +1,90 @@
+#ifndef TESDATA_RECORD_H
+#define TESDATA_RECORD_H
+
+#include "TESFile/Type.h"
+
+#include <QString>
+
+#include <set>
+#include <span>
+
+namespace TESData
+{
+
+using TESFileHandle = int;
+
+class Record final
+{
+public:
+  using Identifier =
+      std::variant<std::monostate, std::uint32_t, std::string, TESFile::Type>;
+
+  [[nodiscard]] TESFile::Type formType() const { return m_FormType; }
+
+  [[nodiscard]] const std::string& file() const { return m_File; }
+
+  [[nodiscard]] const Identifier& identifier() const { return m_Identifier; }
+
+  [[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]] const std::set<TESFileHandle>& alternatives() const
+  {
+    return m_Alternatives;
+  }
+
+  [[nodiscard]] bool ignored() const { return m_Ignored; }
+  void setIgnored(bool value) { m_Ignored = value; }
+
+  void setIdentifier(const Identifier& identifier, std::span<const std::string> files)
+  {
+    m_Identifier = identifier;
+
+    if (std::holds_alternative<std::uint32_t>(m_Identifier)) {
+      std::uint32_t& formId         = std::get<std::uint32_t>(m_Identifier);
+      const std::uint8_t localIndex = formId >> 24U;
+      formId &= ~0xFF000000U;
+      m_File = files[localIndex];
+    }
+  }
+
+  void addAlternative(TESFileHandle origin) { m_Alternatives.insert(origin); }
+
+private:
+  TESFile::Type m_FormType;
+  std::string m_File;
+  Identifier m_Identifier;
+  std::set<TESFileHandle> m_Alternatives;
+  bool m_Ignored = false;
+};
+
+}  // namespace TESData
+
+#endif  // TESDATA_RECORD_H