Add diagnostic output to vite build step

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: 2026-01-12T19:10
+# Build timestamp to force cache invalidation: 2026-01-12T19:15
 
 # Install build dependencies
 RUN apt-get update && apt-get install -y \
@@ -31,8 +31,20 @@ RUN npm install --omit=dev && \
 # Skip jison parser build - pre-built tgnParser.cjs is already in public/lib/
 # RUN tsx tools/buildJisonParser.ts
 
-# Build frontend (generates dist folder) - use local vite binary
-RUN cd app && ./node_modules/.bin/vite build 2>&1
+# Build frontend (generates dist folder) - add diagnostics
+RUN cd app && \
+    echo "=== Node version ===" && \
+    node --version && \
+    echo "=== NPM version ===" && \
+    npm --version && \
+    echo "=== Current directory ===" && \
+    pwd && \
+    echo "=== Directory listing ===" && \
+    ls -la && \
+    echo "=== node_modules/.bin listing ===" && \
+    ls -la node_modules/.bin/ && \
+    echo "=== Starting vite build ===" && \
+    ./node_modules/.bin/vite build
 
 # Build backend with esbuild (handles ESM imports without .js extensions)
 RUN esbuild backend/src/server.ts --bundle --platform=node --target=node20 --format=esm --outfile=backend/dist/server.js --external:express --external:socket.io --external:cors --external:dotenv --external:uuid