feat(docker): Add Docker support for all services

- Create Dockerfiles for all four services (auth, identity, authz, audit)
  - Multi-stage builds using golang:1.25-alpine
  - Minimal runtime images using alpine:latest
  - Copy config files to runtime image

- Create docker-compose.dev.yml for development
  - Only PostgreSQL and Consul
  - Use when running services locally with 'go run'

- Update docker-compose.yml for full deployment
  - All services + infrastructure
  - Services build from Dockerfiles
  - Health checks and dependencies configured
  - Environment variables for service configuration

- Add .dockerignore to optimize build context
  - Excludes docs, tests, IDE files, build artifacts

- Update SUMMARY.md
  - Document both docker-compose files
  - Add Docker deployment section
  - Update file structure to include Dockerfiles

docker-compose.dev.yml

@@ -0,0 +1,49 @@
+# Development docker-compose: Only infrastructure services (PostgreSQL and Consul)
+# Use this for local development when running services directly with `go run`
+
+services:
+  postgres:
+    image: postgres:16-alpine
+    container_name: goplt-postgres
+    environment:
+      POSTGRES_USER: goplt
+      POSTGRES_PASSWORD: goplt_password
+      POSTGRES_DB: goplt
+    ports:
+      - "5432:5432"
+    volumes:
+      - postgres_data:/var/lib/postgresql/data
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U goplt"]
+      interval: 5s
+      timeout: 5s
+      retries: 5
+    networks:
+      - goplt-network
+
+  consul:
+    image: consul:latest
+    container_name: goplt-consul
+    command: consul agent -dev -client=0.0.0.0
+    ports:
+      - "8500:8500"
+    volumes:
+      - consul_data:/consul/data
+    healthcheck:
+      test: ["CMD-SHELL", "consul members"]
+      interval: 10s
+      timeout: 3s
+      retries: 5
+    networks:
+      - goplt-network
+
+volumes:
+  postgres_data:
+    driver: local
+  consul_data:
+    driver: local
+
+networks:
+  goplt-network:
+    driver: bridge
+