Add HAF application testing templates

Add reusable CI templates for HAF-dependent applications:
- .fetch_cache_manager: Standardized cache-manager.sh setup
- .haf_app_detect_changes: Change detection with skip patterns
- .haf_commit_validation: HAF commit consistency validation
- .haf_app_dind_test_base: Docker Compose DinD infrastructure
- .haf_app_tavern_tests: Tavern API testing with parallelization
- Skip rule templates for QUICK_TEST and AUTO_SKIP modes

These templates standardize patterns found across HAfAH,
reputation_tracker, balance_tracker, and hivemind.