Implement basic city portal logic (and severely deabstract)

- Create a podman compose for Postgres
- Implement types and tables for urban data
- No longer use a Cargo workspace as there's no point currently
- Create query functionality (not mutation yet)

podman-compose.yml

@@ -0,0 +1,16 @@
+services:
+  postgres:
+    image: docker.io/library/postgres:alpine
+    container_name: postgres
+    env_file:
+      - .env
+    ports:
+      - "5432:5432"
+    volumes:
+      - ./db/init.sql:/docker-entrypoint-initdb.d/init.sql:Z
+      - postgres_data:/var/lib/postgresql/data:Z
+    restart: unless-stopped
+
+volumes:
+  postgres_data:
+