• [fix] Fix inflated seasonal totals in icclim.sum(...) when converting filtered daily rate data such as precipitation in mm/day to amounts. Seasonal selections like MAM no longer integrate across inter-season gaps, so reproduced cases such as 4228.6 now correctly return 310.4.
• [enh] Add a faster daily-source conversion path for seasonal rate-to-amount handling, preserving the bug fix without paying the full cost of rebuilding sparse seasonal timelines.
• [enh] Add generalized reference-verification scripts and regression tests covering seasonal precipitation and non-precipitation cases, plus a developer protocol for broader Climpact/manual comparisons.
• [fix] Tighten reference-verification summaries so mismatched period coordinates raise an error instead of being compared positionally.