[afurm]

Summary

OPC (ECMA-376) treats package part names as case-insensitive. ZIP central-directory refinement compared entry names with a case-sensitive include?, so archives whose parts were stored as Word/Document.xml or XL/VBAProject.bin stayed on application/x-tika-ooxml (or a non-macro Office type) instead of refining to the document family.

I downcase central-directory entry names before matching them against the discriminating part list, and keep that list in lowercase so the conventional vbaProject.bin spelling still matches.

Test plan

• bundle exec rake test (682 runs, 0 failures)
• Added coverage for mixed-case document parts and mixed-case macro parts

[afurm]

The failing head job looks environmental, not related to this change: it died during bundle install under the 2026-10-15 ruby-head snapshot (BUNDLE_FROZEN with gemfiles/runtime/Gemfile), before any tests ran. That job is marked experimental (continue-on-error), and the same lockfile installs fine on 3.3, 3.4, 4.0, jruby, jruby-head and truffleruby. Nothing here touches dependency resolution. A re-run against a current ruby-head should go green.