v15.1.15

Fix

Correct RFC 5892 Appendix A.4 validation for U+0375 GREEK LOWER NUMERAL SIGN. The validator now checks the Script property of the immediately following character rather than matching the complete remaining label suffix.

This fixes both boundaries:

• a following Greek character remains valid when additional characters follow;
• an intervening non-Greek combining mark is rejected.

Documentation

• Pin UTS #46 to stable Unicode 15.1 revision 31.
• Clarify that named SyntaxError objects apply to the three validator functions, not the separately exported low-level Punycode dependency.
• Clarify the bundled-table wording and update the package-test count.

The bundled Unicode target remains Unicode 15.1.0.

Verification

• All 104 package tests passed.
• All 6,077 applicable nontransitional IdnaTestV2.txt vectors passed.
• Compact Unicode 15.1.0 table source-fidelity verification passed.