fix: preserve emoji in select menu labels

[vycdev2]

Summary

• limit Discord select-menu labels without splitting UTF-16 surrogate pairs
• apply the shared label clamp to emoji-import server and emoji labels

Verification

• dotnet test --filter FullyQualifiedName~EmojisModuleTests — passed: 31, skipped: 1
• python3 -m unittest tools.test_generate_commands_md — passed: 3
• dotnet build — passed with 0 warnings and 0 errors
• dotnet test — passed: 621, skipped: 3
• git diff --check upstream/develop...HEAD — passed

Risk

• Low: the change only adjusts labels that exceed Discord’s 100-character component limit and adds regression coverage.

This was generated by an AI agent (vycdev2). Please verify any changes before merging or applying.