Reformat Docker Compose and add external network

Standardize indentation to a consistent hierarchy and declare the
homelab network as an external resource.

docker-compose.yml

@@ -1,55 +1,58 @@
 services:
-  # PostgreSQL Database
-  postgres:
-    image: postgres:16-alpine
-    container_name: memos-postgres
-    restart: unless-stopped
-    environment:
-      POSTGRES_DB: memos
-      POSTGRES_USER: memos
-      POSTGRES_PASSWORD: zcA3LEfW
-      PGDATA: /var/lib/postgresql/data/pgdata
-    volumes:
-      - postgres_data:/var/lib/postgresql/data
-    healthcheck:
-      test: ["CMD-SHELL", "pg_isready -U memos -d memos"]
-      interval: 10s
-      timeout: 5s
-      retries: 5
-    networks:
-      - homelab
+    # PostgreSQL Database
+    postgres:
+        image: postgres:16-alpine
+        container_name: memos-postgres
+        restart: unless-stopped
+        environment:
+            POSTGRES_DB: memos
+            POSTGRES_USER: memos
+            POSTGRES_PASSWORD: zcA3LEfW
+            PGDATA: /var/lib/postgresql/data/pgdata
+        volumes:
+            - postgres_data:/var/lib/postgresql/data
+        healthcheck:
+            test: ["CMD-SHELL", "pg_isready -U memos -d memos"]
+            interval: 10s
+            timeout: 5s
+            retries: 5
+        networks:
+            - homelab
 
-  # Memos Application
-  memos:
-    build:
-      context: .
-      dockerfile: Dockerfile
-    container_name: memos-app
-    restart: unless-stopped
-    ports:
-      - "8081:8081"
-    environment:
-      # Database configuration
-      MEMOS_DRIVER: postgres
-      MEMOS_DSN: "postgres://memos:zcA3LEfW@postgres:5432/memos?sslmode=disable"
+    # Memos Application
+    memos:
+        build:
+            context: .
+            dockerfile: Dockerfile
+        container_name: memos-app
+        restart: unless-stopped
+        ports:
+            - "8081:8081"
+        environment:
+            # Database configuration
+            MEMOS_DRIVER: postgres
+            MEMOS_DSN: "postgres://memos:zcA3LEfW@postgres:5432/memos?sslmode=disable"
 
-      # Application configuration
-      MEMOS_MODE: prod
-      MEMOS_PORT: 8081
-      MEMOS_DATA: /var/opt/memos
+            # Application configuration
+            MEMOS_MODE: prod
+            MEMOS_PORT: 8081
+            MEMOS_DATA: /var/opt/memos
 
-      # Optional: Set your instance URL
-      # MEMOS_INSTANCE_URL: "https://your-domain.com"
-    volumes:
-      - memos_data:/var/opt/memos
-    depends_on:
-      postgres:
-        condition: service_healthy
-    networks:
-      - homelab
+            # Optional: Set your instance URL
+            # MEMOS_INSTANCE_URL: "https://your-domain.com"
+        volumes:
+            - memos_data:/var/opt/memos
+        depends_on:
+            postgres:
+                condition: service_healthy
+        networks:
+            - homelab
 
 volumes:
-  postgres_data:
-    driver: local
-  memos_data:
-    driver: local
+    postgres_data:
+        driver: local
+    memos_data:
+        driver: local
+networks:
+    homelab:
+        external: true