add .gitignore and Dockerfile for project setup

.gitignore

@@ -0,0 +1,3 @@
+node_modules/
+data/results.json
+.DS_Store

Dockerfile

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+FROM node:20-alpine
+
+WORKDIR /app
+
+# Install dependencies first (cached layer)
+COPY package.json ./
+RUN npm install --omit=dev
+
+# Copy app files
+COPY server.js ./
+COPY public/ ./public/
+COPY images/ ./images/
+
+# HF Spaces requires port 7860
+ENV PORT=7860
+EXPOSE 7860
+
+# Run as non-root (HF Spaces requirement)
+RUN addgroup -S appgroup && adduser -S appuser -G appgroup \
+    && mkdir -p data \
+    && chown -R appuser:appgroup /app
+
+USER appuser
+
+CMD ["node", "server.js"]