Add "abd" to BOUND_GIVEN_NAMES, and let a word in two vocabularies satisfy the join reserve

[derek73]

abd Allah Smith read given abd, middle Allah, where abdul Rahman Smith reads given abdul Rahman. The spellings that write the article as its own word — Abd Allah, Abd al-Rahman — match none of abdul/abdel/abdal, and the Arabic-script عبد has covered the same word since #269, so only the Latin side was short.

abd Allah Smith          ->  given='abd Allah'   family='Smith'      (was given='abd', middle='Allah')
Smith, abd Allah         ->  given='abd Allah'   family='Smith'
abd Rahman Ahmed Salem   ->  given='abd Rahman'  middle='Ahmed'      (pairwise, like abdul)

Why the wordlist alone doesn't do it

abd is also the postnominal ABD ("All But Dissertation") in SUFFIX_ACRONYMS. The join's reserve counted every piece except titles and suffixes — so the bound word's own piece didn't count toward the three it needed, and the rule declined silently on the common three-word shape. Adding the word and stopping there changes nothing:

                                  abd Allah Smith        Jane Smith, ABD
wordlist only                     unchanged (broken)     suffix='ABD'
+ move to acronyms-ambiguous      given='abd Allah'      given='ABD'  <- credential lost
+ drop from SUFFIX_ACRONYMS       given='abd Allah'      family='ABD' <- credential lost
+ fix the reserve count           given='abd Allah'      suffix='ABD'

The last row is this PR. The claimed piece now counts, which is what the reserve means: it asks whether enough other words are left to spare, and the piece the rule has already claimed as a name is not one of them to spare. Both readings survive — position tells them apart, so Jane Smith ABD, Jane Smith, ABD and Jane Smith A.B.D. all still read the credential as a suffix.

Same shape as #397

Dual set membership shrinking a count that gates a rule is exactly the Catalan i finding — there it shrinks the rootname count P3's single-letter carve-out tests. Second instance in two days. The general question (should membership in one set suppress a word from a count gating a rule keyed on another?) stays open on #397; this PR fixes only the instance in front of it, where the count was wrong on its own terms.

Verification

abd is the only shipped word in both sets — measured, not assumed — so nothing else can move. All 751 differential corpus names are byte-identical and the harness reports 0 unexplained at the 1.4.0 baseline. The corpus contains no abd name, so that is a blast-radius check, not evidence for the fix; the evidence is the tests.

Mutation-verified: reverting the count line alone puts abd Allah Smith back to given abd. The stage-level test in test_group.py uses a synthetic word in both vocabularies, so it pins the mechanism rather than the wordlist, and asserts the reserve still declines at two name words.

3522 tests pass, mypy clean. Per-word evidence comments added on both sides of the collision, in the #: style, so a future editor of either set sees the other.

🤖 Generated with Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.53%. Comparing base (55a7822) to head (0b11278).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #400   +/-   ##
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  Coverage   98.53%   98.53%           
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  Files          44       44           
  Lines        2942     2942           
=======================================
  Hits         2899     2899           
  Misses         43       43           

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