fix: handle absolute paths correctly in environment variable expansion

Fixed issue where absolute paths from environment variables (like $COMFYUI_ROOT=/workspace/ComfyUI) were being treated as relative paths and prepended with the config directory.

Now checks if the expanded path is absolute (starts with /) and uses it as-is, otherwise treats it as relative to the config file directory.

Before: /home/valknar/Projects/runpod//workspace/ComfyUI
After: /workspace/ComfyUI

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

artifact_git_download.sh

@@ -417,9 +417,15 @@ install_lib() {
       return 1
     fi
 
-    # Custom directory relative to config file directory
-    local config_dir=$(dirname "$(realpath "${config_file}")")
-    lib_dir="$config_dir/$expanded_into"
+    # Check if expanded path is absolute or relative
+    if [[ "$expanded_into" == /* ]]; then
+      # Absolute path - use as-is
+      lib_dir="$expanded_into"
+    else
+      # Relative path - make relative to config file directory
+      local config_dir=$(dirname "$(realpath "${config_file}")")
+      lib_dir="$config_dir/$expanded_into"
+    fi
   else
     # Use global .arty/libs for libraries without custom 'into'
     lib_dir="$ARTY_LIBS_DIR/$lib_name"