Slash-command autocomplete fails to match non-ASCII (CJK/Chinese) command names when filtering (v2.1.161, macOS)

Summary

Custom slash commands with non-ASCII (Chinese / CJK) names no longer appear in the / autocomplete dropdown when you type to filter. The commands are still loaded — they show when you type only / — but typing any CJK character to filter removes the CJK-named commands.

Environment

• Claude Code: 2.1.161
• OS: macOS
• Commands: ~/.claude/commands/*.md (valid frontmatter with description:)

Repro

1. Create a command with a CJK filename, e.g. ~/.claude/commands/盤前並行.md.
2. Type just / — 盤前並行 / 當沖戰情室 appear in the list. ✅
3. Type /盤 or /當 (CJK filter text) — the matching CJK-named commands are filtered out and disappear. ❌
4. ASCII-named commands (e.g. pm.md) filter correctly when typing Latin characters.

Expected

Typing CJK characters should fuzzy-match CJK command names, the same way ASCII input matches ASCII names.

Actual

The autocomplete filter does not match CJK input against CJK command names; CJK commands are only visible with an empty filter (bare /).

Notes

• Regression: worked through ~2026-06-02, broke ~2026-06-03 after a version update; the command files themselves were unchanged.
• Not deprecation / file-size / missing-file — the commands load and appear with bare /.
• Likely a regression in the autocomplete fuzzy-matcher's handling of non-ASCII / multi-byte input.
• Workaround: give commands ASCII-typeable names.