feat: add Phase 4 DinD test templates for HAF apps

Add composable templates for Docker Compose test environments:
- .haf_app_dind_test_variables: Standard variables for DinD tests
- .haf_app_dind_extract_cache: Cache extraction with blockchain handling
- .haf_app_dind_compose_startup: ci.env creation and compose startup
- .haf_app_dind_wait_for_services: PostgreSQL/PostgREST wait with DNS fix
- .haf_app_dind_compose_teardown: Log collection and cleanup
- .haf_app_dind_complete_test: Complete ready-to-use test template

These templates reduce duplication found in balance_tracker and
reputation_tracker test jobs by providing reusable building blocks
for the common DinD test pattern:
1. Extract sync cache
2. Handle blockchain symlinks/copies
3. Start docker-compose services
4. Wait for PostgreSQL and PostgREST
5. Run tests
6. Collect logs and cleanup