Closes the two coverage gaps a temporal-completeness audit surfaced (the code
was already correct, just untested):
- changedBetween / generationsTouching include un-flushed PENDING generations
and stay identical across the flush — the building blocks of since/diff/history
see single-op writes with no forced flush.
- setRetentionBudget() drives adaptive auto-compaction on flush() down to the
byte budget: history is reclaimed, the live record is untouched (the cor #65
retention-consume wiring, proven end-to-end).
65 generation/temporal tests green; 1528 unit green.
David Snelling
3783e61b30