infra(docker): add Docker Compose with PostgreSQL and Keycloak

- Add docker-compose.yml (v3.9) with postgres:16-alpine and keycloak:26.1 services
- Configure PostgreSQL with separate workclub and keycloak databases
- Setup Keycloak with database backend, admin user, and realm import capability
- Create PostgreSQL init script to provision development databases and users
- Add placeholder realm-export.json for Keycloak realm configuration
- Configure healthchecks and app-network bridge for service discovery
- Document configuration and patterns in learnings.md

.sisyphus/evidence/task-2-config-verification.txt

@@ -0,0 +1,83 @@
+TASK 2: Docker Compose Configuration Verification
+================================================
+
+Generated: 2026-03-03
+
+## Configuration Files Created
+
+✓ /docker-compose.yml - Main Docker Compose configuration
+✓ /infra/keycloak/realm-export.json - Placeholder realm export
+✓ /infra/postgres/init.sql - PostgreSQL initialization script
+
+## YAML Syntax Validation
+
+✓ docker-compose.yml structure verified:
+  - services: postgres, keycloak
+  - volumes: postgres-data
+  - networks: app-network
+
+## Configuration Details
+
+### PostgreSQL Service (postgres)
+- Image: postgres:16-alpine
+- Port: 5432
+- Databases:
+  * postgres (system)
+  * workclub (application, user: app, password: devpass)
+  * keycloak (Keycloak metadata, user: keycloak, password: keycloakpass)
+- Volume: postgres-data (/var/lib/postgresql/data)
+- Healthcheck: pg_isready -U postgres
+- Network: app-network
+
+### Keycloak Service (keycloak)
+- Image: quay.io/keycloak/keycloak:26.1
+- Port: 8080
+- Admin: admin/admin
+- Database: keycloak (PostgreSQL)
+- Command: start-dev --import-realm
+- Realm Import: /opt/keycloak/data/import mounted to ./infra/keycloak
+- Healthcheck: /health/ready endpoint
+- Network: app-network
+- Depends on: postgres (healthy)
+
+## Environment Notes
+
+Docker Engine: 29.2.1
+Docker Compose: Not available (would require docker compose CLI plugin)
+
+NOTE: Full integration test (docker compose up -d) cannot run in this environment.
+However, configuration is syntactically valid and follows Docker Compose v3.9 specification.
+
+## Service Dependencies
+
+keycloak → depends_on postgres (service_healthy condition)
+Both services connected via app-network bridge network
+
+## Verification Summary
+
+✓ YAML Syntax: Valid
+✓ Service Definition: Both postgres and keycloak properly configured
+✓ Environment Variables: All required vars present
+✓ Volumes: postgres-data volume declared, keycloak realm import mount configured
+✓ Networks: app-network bridge network declared
+✓ Healthchecks: Configured for both services
+✓ Database Setup: init.sql script creates workclub and keycloak databases with proper users
+
+## Known Limitations
+
+- docker compose CLI plugin not available in this environment
+- Cannot perform runtime health verification (docker compose up)
+- Cannot test OIDC discovery endpoint connectivity
+- Manual Docker deployment would require: docker run commands or alternative orchestration
+
+## File Structure
+
+/Users/mastermito/Dev/opencode/
+├── docker-compose.yml
+├── infra/
+│   ├── postgres/
+│   │   └── init.sql
+│   └── keycloak/
+│       └── realm-export.json
+
+All files are in place and ready for Docker deployment.