Read-memory estimate is slightly low for tiny uncompressed tiles #157

Finding (as written in the restart doc, "Known follow-ups"): the read-memory estimate is slightly low for tiny uncompressed tiles.

Suggested fix: include the per-tile overhead in the estimate (or a safe lower bound), and add a test with a tiny uncompressed tiled TIFF that the estimate covers.

Source: restart doc "Known follow-ups, not blocking the release" (2026-11-04).