Initial commit: LMS microservices scaffold

- Gradle multi-module: libs/{common-http,security-jwt,markdown,test-support},
  services/{identity,academic,progress,gateway}, web (Thymeleaf+htmx)
- identity-service: JWT auth (RSA), accounts, students, groups, enrollment,
  import from XLSX/CSV, credentials export, password reset
- academic-service: lab import from JSON/zip (markdown + YAML + variants),
  levels, API
- progress-service: schema for student levels and variant assignments
- gateway: Spring Cloud Gateway, JWT validation, route propagation
- web: Server-side UI with flex/footer layout, light/dark theme toggle,
  admin dashboard, groups CRUD, student portal placeholder
- docker-compose: PostgreSQL 18
- Tests: identity smoke test with Testcontainers

docker-compose.yml

@@ -0,0 +1,22 @@
+# Local development infrastructure. Start PostgreSQL 18 with: docker compose up -d postgres
+services:
+  postgres:
+    image: postgres:18
+    container_name: lms-postgres
+    environment:
+      POSTGRES_DB: ${LMS_DB_NAME:-lms}
+      POSTGRES_USER: ${LMS_DB_USER:-lms}
+      POSTGRES_PASSWORD: ${LMS_DB_PASSWORD:-lms}
+    ports:
+      - "${LMS_DB_PORT:-5432}:5432"
+    volumes:
+      # PostgreSQL 18+ stores data under a versioned subdirectory of /var/lib/postgresql.
+      - lms_pgdata:/var/lib/postgresql
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U ${LMS_DB_USER:-lms} -d ${LMS_DB_NAME:-lms}"]
+      interval: 5s
+      timeout: 3s
+      retries: 10
+
+volumes:
+  lms_pgdata: