Fix runtime heatmap cache accounting

[adrunkhuman]

Summary

• fix runtime cache accounting so heatmap projection memory includes work_indexes
• keep the runtime memory logs aligned with the actual resident projection footprint
• close Investigate climate.duckdb size and a leaner runtime schema #75 now that the live runtime split looks good and only this small accounting bug remained

Verification

• uv run pytest tests/test_climate_repository.py
• pre-commit hooks passed during git commit

Closes #75.