[iliaal]

Summary

• Require every grapheme in a candidate combined-initial token to satisfy the existing initial predicate before expanding it.
• Preserve digits, punctuation, and caseless characters inside their original token. For example, Smith, A1 John now retains first name A1 instead of promoting 1 to the first name and exporting A as an initial.
• Keep plain, dotted, and decomposed-letter initials working and retain the existing expansion ceiling.
• Add isolated mapper/parser regressions and an Unreleased changelog entry.

Verification

• PHP 8.4.24: full PHPUnit suite passes, 1,220 tests / 3,156 assertions (also independently repeated during review).
• Regression file: 10 tests / 21 assertions; nine cases fail on the original code.
• PHPStan level 9 and PHP 8.5 configuration pass with --memory-limit=512M (the local 128 MB default was insufficient).
• PHP-CS-Fixer dry run, empty-baseline guard, PHP 8.5 deprecation guard, README check, and git diff --check pass.
• Full remote tree contents and modes match the tested local tree 8e75a8d0ecad1d5e2263e9af63b80231dfebac91 before opening this PR.
• Local runtime is PHP 8.4 only; the CI matrix covers PHP 8.3, 8.4, and 8.5.

No dependencies, workflows, or public signatures changed.