Fix: correct esbuild output path and remove redundant COPY step

- Output backend build to dist/backend/src/server.js to match package.json
- ONNX files are already in pre-built dist, no need to copy separately

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: 2026-01-12T19:50
+# Build timestamp to force cache invalidation: 2026-01-12T20:00
 
 # Install build dependencies
 RUN apt-get update && apt-get install -y \
@@ -14,12 +14,9 @@ RUN apt-get update && apt-get install -y \
 # Create app directory
 WORKDIR /app
 
-# Copy trigo-web project (includes pre-built app/dist)
+# Copy trigo-web project (includes pre-built app/dist with onnx files)
 COPY trigo-web/ ./
 
-# Remove large ONNX files from public (already in dist)
-RUN rm -rf public/onnx
-
 # Install build tools globally
 RUN npm install -g tsx jison typescript esbuild
 
@@ -32,13 +29,12 @@ RUN npm install --omit=dev && \
     cd ..
 
 # Skip jison parser build - pre-built tgnParser.cjs is already in public/lib/
-# Skip vite build - pre-built dist is already included
+# Skip vite build - pre-built dist is already included (with onnx files)
 
 # 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
-
-# Copy ONNX files to dist (they don't need to be in public anymore)
-COPY trigo-web/public/onnx/ ./app/dist/onnx/
+# Output to dist/backend/src/ to match backend/package.json main field
+RUN mkdir -p backend/dist/backend/src && \
+    esbuild backend/src/server.ts --bundle --platform=node --target=node20 --format=esm --outfile=backend/dist/backend/src/server.js --external:express --external:socket.io --external:cors --external:dotenv --external:uuid
 
 # Set environment variables for Hugging Face Spaces
 ENV PORT=7860