Add Windows build scripts, fix multi-threaded MPQ extraction, and cross-platform temp paths

- Add build.ps1/bat, rebuild.ps1/bat, debug_texture.ps1/bat (Windows equivalents
  of existing bash scripts, using directory junctions for Data link)
- Fix asset extractor: StormLib is not thread-safe even with separate handles per
  thread. Serialize all MPQ reads behind a mutex while keeping CRC computation and
  disk writes parallel. Previously caused 99.8% extraction failures with >1 thread.
- Add SFileHasFile() check during enumeration to skip listfile-only entries
- Add diagnostic logging for extraction failures (first 5 per thread + summary)
- Use std::filesystem::temp_directory_path() instead of hardcoded /tmp/ in
  character_renderer.cpp debug dumps
- Update debug_texture.sh to use $TMPDIR fallback and glob for actual dump filenames

src/rendering/character_renderer.cpp

@@ -812,10 +812,10 @@ VkTexture* CharacterRenderer::compositeTextures(const std::vector<std::string>&
         }
     }
 
-    // Debug: dump composite to /tmp for visual inspection
+    // Debug: dump composite to temp dir for visual inspection
     {
-        std::string dumpPath = "/tmp/wowee_composite_debug_" +
-            std::to_string(width) + "x" + std::to_string(height) + ".raw";
+        std::string dumpPath = (std::filesystem::temp_directory_path() / ("wowee_composite_debug_" +
+            std::to_string(width) + "x" + std::to_string(height) + ".raw")).string();
         std::ofstream dump(dumpPath, std::ios::binary);
         if (dump) {
             dump.write(reinterpret_cast<const char*>(composite.data()),