fix(#459): repair one-case suffix acronyms to all-caps in case repair

[IMGillusion]

What

HumanName('JOHN SMITH MBA').capitalize() returned 'John Smith Mba' — a credential acronym title-cased as an ordinary word (#459).

CAPITALIZATION_EXCEPTIONS only carries the five pieces that need non-all-caps spelling (md, phd, ii, iii, iv); every other suffix_acronyms entry fell through to str.capitalize() and got title-cased (mba -> Mba, jd -> Jd, qc -> Qc, mp -> Mp).

Fix

In _cap_word, after the exceptions-map lookup and before the Mac/Mc rule, a word whose period-free form is a known suffix_acronyms entry repairs to word.upper().

Gated on role is Role.SUFFIX so a word that is in the vocabulary but parsed as a family name (anh van do -> Anh Van Do) still repairs as an ordinary name word, not an acronym. The exceptions map is consulted first, so md -> M.D. and phd -> Ph.D. are unchanged.

Out of scope

The issue's QC MP example: the parser assigns QC the GIVEN role and MP the SUFFIX role, so only MP repairs to caps here. Uppercasing a word merely because it is a given name would break ordinary names that share a spelling with an acronym (e.g. ed -> ED), so the GIVEN case is left to the parser. Flagging it here rather than widening the gate.

Docs & tests

• New examples in tests/test_capitalization.py (all-caps suffix, exceptions still win, family-name-in-vocab stays title-case).
• rules.md R4: added a john smith mba example; regenerated tools/differential/corpus_rules.jsonl.

Full suite: 7610 passed, 179 skipped, 4 xfailed.