Fix IDs always 0, broken dates, and Swagger UI localhost URLs
- Task.setEntity: read id first, then parse date via getString to avoid SQLite JDBC timestamp parse error that silently skipped id assignment
- Task: rename column reference tid -> id to match actual DB schema
- MyHandler: use relative /api-docs URL instead of hardcoded localhost
- swagger3.yml: remove servers block so Swagger UI uses current host
- docker-compose.yml: add restart: unless-stopped