v3.1.0

Everything since v3.0.0 in one cut: the FY27 example shift, the palette restyle, the deterministic clean-up tooling, the GST legislative scope note, and a run of help corrections.

Highlights:

• Every worked example starts 1 July 2026 (FY27); help text re-dated to match with column alignment preserved.
• palette pass across the workbook; printer settings, saved paths and always-calculate flags stripped; the zip rebuilds deterministically.
• oz.GSTAddλ and oz.GSTExtractλ spill a legislative scope note: GST Act 1999 ss 9-70 and 9-75, arithmetic only.
• Help corrections: CorkscrewλDV, AboutFinancialλ, the four CountCols index rows, two <Coming Soon> WEBPAGE rows, and this cut's pair - oz.CurrentRatioλ and oz.ROIλ no longer link their neighbours' Investopedia articles.
• The oz.SumContainsλ tab now carries the λ every sibling has.
• Postbuild passes are tracked, idempotent tools in tools/postbuild/ with asserted hit counts and CI coverage.

Gates at release: verify_workbook 130 functions and 211 parts, verify_sources, verify_signatures 117 signatures, verify_previous_names 130 of 130, verify_index, verify_afe, Excel selftest 259 assertions 0 failed, verify_cache all 20,228 cached values match their formulas.