fix: follow symlinks when calculating model disk usage

HuggingFace models use symlinks pointing to blobs in the cache. The stat
command was returning the size of the symlink itself (76 bytes) instead of
the actual file it points to.

Fixed by:
- Adding -L flag to stat commands to follow symlinks
- Testing which stat format works (Linux -c vs macOS -f) before executing
- Using proper spacing and quotes in stat commands
- Checking for both regular files and symlinks in the condition

This fixes disk usage showing as 1 KB instead of the actual ~50+ GB for models
like FLUX.

artifact_huggingface_download.sh

@@ -607,9 +607,17 @@ get_model_disk_usage() {
 
     local total_bytes=0
     while IFS= read -r file_path; do
-        if [[ -f "$file_path" ]]; then
+        if [[ -f "$file_path" ]] || [[ -L "$file_path" ]]; then
             local file_size
-            file_size=$(stat -f%z "$file_path" 2>/dev/null || stat -c%s "$file_path" 2>/dev/null || echo "0")
+            # Use -L to follow symlinks (HuggingFace uses symlinks to blobs)
+            # Try Linux stat first, then macOS stat
+            if stat -L -c "%s" "$file_path" >/dev/null 2>&1; then
+                file_size=$(stat -L -c "%s" "$file_path" 2>/dev/null)
+            elif stat -L -f "%z" "$file_path" >/dev/null 2>&1; then
+                file_size=$(stat -L -f "%z" "$file_path" 2>/dev/null)
+            else
+                file_size=0
+            fi
             total_bytes=$((total_bytes + file_size))
         fi
     done <<< "$model_files"