chore: restructure project into backend and frontend folders

- Move all frontend code to frontend/ directory
- Add backend/ with Go project structure (cmd, internal, pkg)
- Add docker-compose.yml for orchestration

frontend/Dockerfile

@@ -0,0 +1,29 @@
+# syntax=docker/dockerfile:1
+
+# Stage 1: Build
+FROM node:20-alpine AS builder
+
+WORKDIR /app
+
+# Copy package files
+COPY package.json yarn.lock ./
+RUN yarn install --frozen-lockfile
+
+# Copy source code
+COPY . .
+
+# Build application
+RUN yarn build
+
+# Stage 2: Production
+FROM nginx:alpine AS production
+
+# Copy custom nginx config
+COPY nginx.conf /etc/nginx/conf.d/default.conf
+
+# Copy built files from builder stage
+COPY --from=builder /app/dist /usr/share/nginx/html
+
+EXPOSE 80
+
+CMD ["nginx", "-g", "daemon off;"]