feat(zone): read zone files of every version the client reads

Zone files older than version 30 were refused. The client reads them
(1.10.64):
- LuzFile::ReadLUZFile reads a version below 20 as 20;
- LuzReader::ReadScenes reads a scene of a version 20-29 file as a bare
  u32 SceneTable ID, with no file name;
- ZoneLoader::ReadZoneFile takes those scenes in SceneTable ID order,
  looks each one up in the CDClient SceneTable and, when there is a
  row, makes it a scene with the next index (0, 1, ...; -1 past 255) as
  its ID and the row's sceneName as its file; a scene with no row is
  left out.

ZoneFile now reads these files (FileFormatVersion::Oldest = 20 for
anything older), keeps the SceneTable ID on ZoneScene::sceneTableID,
and ZoneFile::ResolveSceneTable does the lookup the client does; the
world looks the names up in the CDClient SceneTable.

The only such file on disk (version 20) now reads.

Check in game: nothing to check on live worlds (all are version 36+).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

dCommon/ZoneFile.h

@@ -1,6 +1,8 @@
 #pragma once
 
 #include <cstdint>
+#include <functional>
+#include <optional>
 #include <iosfwd>
 #include <map>
 #include <string>
@@ -27,6 +29,7 @@ struct WaypointCommand {
 struct ZoneScene {
 	std::string filename;
 	uint32_t id{};
+	uint32_t sceneTableID{}; // before PrePreAlpha: the scene's row in the CDClient SceneTable (see ResolveSceneTable)
 	eSceneType sceneType{};
 	std::string name;
 	NiPoint3 unknown1;
@@ -199,6 +202,7 @@ struct Path {
 
 struct ZoneFile {
 	enum class FileFormatVersion : uint32_t { //Times are guessed.
+		Oldest = 20, // the client reads anything older as this
 		PrePreAlpha = 30,
 		PreAlpha = 32,
 		LatePreAlpha = 33,
@@ -243,6 +247,13 @@ struct ZoneFile {
 	 */
 	void ReadHeader(std::istream& file);
 
+	/**
+	 * Before PrePreAlpha a scene is only its SceneTable ID. As the client does (ZoneLoader::ReadZoneFile), the scenes
+	 * are taken in SceneTable ID order, each one `sceneName` finds a row for gets that row's sceneName as its file and
+	 * name and the next index as its ID, and the others are left out. Nothing to do for newer files.
+	 */
+	void ResolveSceneTable(const std::function<std::optional<std::string>(uint32_t)>& sceneName);
+
 private:
 	void ReadScene(std::istream& file);
 	void ReadZoneBoundaries(std::istream& file);