feat: UGC server that makes and serves player models' meshes and icons

A new server (dUgcServer, started by master with enable_ugc_server=1) that
takes unprocessed ugc and ugc_modular_build rows from the database and makes
what the client downloads with UGCUSE3DSERVICES: an optimized NIF (hidden
faces removed, ambient occlusion baked into vertex colors) and a 128px DDS
icon for player models, rendered by a software rasterizer from the client's
LDD brick primitives, and icons for cars and rockets assembled from their
modules per ModularBuildComponent/ModuleComponent. It serves them, with the
models' LXFML, over HTTP in the client's UGCC<dc>/3DOPTIMIZED and
IMAGE128DDS layout with .gz and .checksum files, and keeps its folder under
a size cap.

Processing state lives in ugc.is_optimized plus new processed_at,
process_attempts and process_error columns (and the same on
ugc_modular_build). ServiceType::UGC is appended. NifFile moves to dCommon
and records named node transforms for the modules' attach points.

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

CMakeLists.txt

@@ -133,7 +133,7 @@ endif()
 message(STATUS "Variable: DLU_CONFIG_DIR = ${DLU_CONFIG_DIR}")
 
 # Copy resource files on first build
-set(RESOURCE_FILES "sharedconfig.ini" "authconfig.ini" "chatconfig.ini" "worldconfig.ini" "masterconfig.ini" "dashboardconfig.ini" "blocklist.dcf")
+set(RESOURCE_FILES "sharedconfig.ini" "authconfig.ini" "chatconfig.ini" "worldconfig.ini" "masterconfig.ini" "dashboardconfig.ini" "ugcconfig.ini" "blocklist.dcf")
 message(STATUS "Checking resource file integrity")
 
 include(Utils)
@@ -330,6 +330,7 @@ add_subdirectory(dWorldServer)
 add_subdirectory(dAuthServer)
 add_subdirectory(dChatServer)
 add_subdirectory(dDashboardServer)
+add_subdirectory(dUgcServer)
 add_subdirectory(dMasterServer) # Add MasterServer last so it can rely on the other binaries
 
 target_precompile_headers(