fix(planner): align Elastic window validation

[milindsrivastava1997]

Summary

• reject Elastic queries whose repetition interval is shorter than the ingestion interval
• reject temporal Elastic ranges shorter than the repetition interval
• preserve the one-ingestion-interval exception and valid t_repeat window sizing
• update and extend Elastic integration coverage

Validation

• cargo fmt --all -- --check
• cargo test -p asap_planner

Closes #485