Debug: add non-failing directory structure check

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

Dockerfile

@@ -3,7 +3,7 @@ FROM node:20-slim
 # Set noninteractive installation
 ENV DEBIAN_FRONTEND=noninteractive
 
-# Build timestamp to force cache invalidation: 2026-01-12T20:25
+# Build timestamp to force cache invalidation: 2026-01-12T20:30
 
 # Install build dependencies
 RUN apt-get update && apt-get install -y \
@@ -33,9 +33,15 @@ RUN npm install --omit=dev && \
 # - Backend: backend/dist/backend/src/server.js
 # - Parser: public/lib/tgnParser.cjs
 
-# Verify pre-built files exist
-RUN ls -la backend/dist/backend/src/server.js && \
-    ls -la app/dist/index.html
+# Debug: Show directory structure (use ; so it doesn't fail the build)
+RUN echo "=== Directory structure ===" ; \
+    pwd ; \
+    ls -la ; \
+    echo "=== app/ ===" ; ls -la app/ 2>&1 ; \
+    echo "=== app/dist/ ===" ; ls -la app/dist/ 2>&1 ; \
+    echo "=== backend/ ===" ; ls -la backend/ 2>&1 ; \
+    echo "=== backend/dist/ ===" ; ls -la backend/dist/ 2>&1 ; \
+    echo "=== Done ===" || true
 
 # Set environment variables for Hugging Face Spaces
 ENV PORT=7860