chore(docker): optimize Dockerfiles and add healthchecks for Coolify deployment

- Add build arguments and environment variables for OAuth client IDs in frontend Dockerfile
- Install wget and add HEALTHCHECK commands to frontend and backend Dockerfiles
- Create non-root user in backend Dockerfile for improved security
- Update docker-compose.yml with healthcheck configurations and dynamic port/environment variable support
- Add network configuration and restart policies to docker-compose services
- Expand .env.example with additional OAuth secrets, ports, and environment variables for Coolify
- Enhance README.md with detailed Coolify deployment instructions and required environment variables table

Dockerfile

@@ -1,8 +1,18 @@
-# Frontend Dockerfile
+# Frontend Dockerfile (Coolify Optimized)
 FROM node:20-alpine AS builder
 
 WORKDIR /app
 
+# Build arguments for environment variables
+ARG VITE_MS_CLIENT_ID
+ARG VITE_GOOGLE_CLIENT_ID
+ARG VITE_API_URL
+
+# Set as environment variables for build
+ENV VITE_MS_CLIENT_ID=$VITE_MS_CLIENT_ID
+ENV VITE_GOOGLE_CLIENT_ID=$VITE_GOOGLE_CLIENT_ID
+ENV VITE_API_URL=$VITE_API_URL
+
 # Copy package files
 COPY package*.json ./
 
@@ -18,6 +28,9 @@ RUN npm run build
 # Production stage
 FROM nginx:alpine
 
+# Install wget for healthcheck
+RUN apk add --no-cache wget
+
 # Copy built assets
 COPY --from=builder /app/dist /usr/share/nginx/html
 
@@ -26,4 +39,7 @@ COPY nginx.conf /etc/nginx/conf.d/default.conf
 
 EXPOSE 80
 
+HEALTHCHECK --interval=30s --timeout=10s --start-period=5s --retries=3 \
+    CMD wget -q --spider http://localhost:80 || exit 1
+
 CMD ["nginx", "-g", "daemon off;"]