feat: add complete Kubernetes deployment infrastructure

Add production-ready deployment configuration for Raspberry Pi cluster with comprehensive documentation and automation scripts.

Kubernetes Manifests (deploy/k8s/):
- namespace.yaml - Dedicated namespace for the application
- configmap.yaml - Environment configuration (MongoDB URI, ports, URLs)
- secrets.yaml.example - Template for sensitive credentials (JWT, Cloudinary, Stripe)
- mongodb-statefulset.yaml - MongoDB with persistent storage, placed on Pi 5 nodes (ARM64)
- backend-deployment.yaml - Backend with 2 replicas, prefers Pi 5 nodes, health checks
- frontend-deployment.yaml - Frontend with 2 replicas, can run on any node, nginx-based
- ingress.yaml - Traefik/NGINX ingress for API, Socket.IO, and frontend routing

Docker Configuration:
- backend/Dockerfile - Multi-stage build for ARM64/ARMv7 with health checks
- backend/.dockerignore - Excludes tests, coverage, node_modules from build
- frontend/Dockerfile - Multi-stage build with nginx, optimized for ARM
- frontend/.dockerignore - Excludes dev files from production build
- frontend/nginx.conf - Production nginx config with gzip, caching, React Router support

Resource Optimization for Pi Cluster:
- MongoDB: 512Mi-2Gi RAM, 250m-1000m CPU (Pi 5 only, ARM64 affinity)
- Backend: 256Mi-512Mi RAM, 100m-500m CPU (prefers Pi 5, ARM64)
- Frontend: 64Mi-128Mi RAM, 50m-200m CPU (any node, lightweight)
- Total: ~3.5GB RAM minimum, perfect for 2x Pi 5 (8GB) + 1x Pi 3B+ (1GB)

Automation Scripts (deploy/scripts/):
- build.sh - Build multi-arch images (ARM64/ARMv7) and push to registry
- deploy.sh - Deploy all Kubernetes resources with health checks and status reporting
- Both scripts include error handling, color output, and comprehensive logging

Documentation (deploy/README.md):
- Complete deployment guide with prerequisites
- Step-by-step instructions for building and deploying
- Verification commands and troubleshooting guide
- Scaling, updating, and rollback procedures
- Resource monitoring and cleanup instructions
- Security best practices and performance optimization tips

Health Endpoints:
- Backend: GET /api/health (status, uptime, MongoDB connection)
- Frontend: GET /health (nginx health check)
- Used by Kubernetes liveness and readiness probes

Key Features:
- Multi-architecture support (ARM64 for Pi 5, ARMv7 for Pi 3B+)
- NodeAffinity places heavy workloads (MongoDB, backend) on Pi 5 nodes
- Persistent storage for MongoDB (10Gi PVC)
- Horizontal pod autoscaling ready
- Zero-downtime deployments with rolling updates
- Comprehensive health monitoring
- Production-grade nginx with security headers
- Ingress routing for API, WebSocket, and static assets

Security:
- Secrets management with Kubernetes Secrets
- secrets.yaml excluded from Git (.gitignore)
- Minimal container images (alpine-based)
- Health checks prevent unhealthy pods from serving traffic
- Security headers in nginx (X-Frame-Options, X-Content-Type-Options, etc.)

Usage:
1. Build images: ./deploy/scripts/build.sh
2. Configure secrets: cp deploy/k8s/secrets.yaml.example deploy/k8s/secrets.yaml
3. Deploy: ./deploy/scripts/deploy.sh
4. Monitor: kubectl get all -n adopt-a-street

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

backend/.dockerignore

@@ -0,0 +1,15 @@
+node_modules
+npm-debug.log
+.env
+.env.local
+.env.*.local
+coverage
+__tests__
+*.test.js
+.git
+.gitignore
+README.md
+.vscode
+.idea
+uploads/*
+!uploads/.gitkeep

backend/Dockerfile

@@ -0,0 +1,38 @@
+# Multi-stage build for ARM compatibility (Raspberry Pi)
+FROM node:18-alpine AS builder
+
+WORKDIR /app
+
+# Copy package files
+COPY package*.json ./
+
+# Install dependencies
+RUN npm ci --only=production
+
+# Copy source code
+COPY . .
+
+# --- Production stage ---
+FROM node:18-alpine
+
+# Install curl for health checks
+RUN apk add --no-cache curl
+
+WORKDIR /app
+
+# Copy dependencies from builder
+COPY --from=builder /app/node_modules ./node_modules
+COPY --from=builder /app .
+
+# Create uploads directory
+RUN mkdir -p uploads
+
+# Expose port
+EXPOSE 5000
+
+# Health check
+HEALTHCHECK --interval=30s --timeout=3s --start-period=40s \
+  CMD node -e "require('http').get('http://localhost:5000/api/health', (r) => {process.exit(r.statusCode === 200 ? 0 : 1)})"
+
+# Start server
+CMD ["node", "server.js"]

backend/server.js

@@ -115,6 +115,16 @@ app.use("/api/auth/register", authLimiter);
 app.use("/api/auth/login", authLimiter);
 app.use("/api", apiLimiter);
 
+// Health check endpoint (for Kubernetes liveness/readiness probes)
+app.get("/api/health", (req, res) => {
+  res.status(200).json({
+    status: "healthy",
+    timestamp: new Date().toISOString(),
+    uptime: process.uptime(),
+    mongodb: mongoose.connection.readyState === 1 ? "connected" : "disconnected",
+  });
+});
+
 // Routes
 app.use("/api/auth", authRoutes);
 app.use("/api/streets", streetRoutes);