Slash command autocomplete inserts display label instead of resolved command name

Description

When typing a slash command and selecting a suggestion from the autocomplete popup, the inserted text is the human-readable display label rather than the fully-resolved command name. This causes the command to fail to parse on submit.

Steps to reproduce

1. Start typing a slash command whose display name contains a space (e.g. a plugin-provided command displayed as /My Command that resolves internally to /plugin-name:command-name).
2. The autocomplete popup correctly shows and highlights the matching command.
3. Select the suggestion / press Enter.
4. The input is submitted as the literal display label (e.g. /My Command) rather than the resolved command name.
5. This gets parsed as the base command plus a trailing argument (e.g. /My with argument Command), which fails.
6. Result: Unknown command: /My.

Expected behavior

Selecting the autocomplete suggestion should insert the fully-qualified, parseable command name, not the display label shown in the popup.

Workaround

Typing the full resolved slash command directly (e.g. /plugin-name:command-name) works correctly.

Environment

• Claude Code CLI
• Reproduced with a plugin-provided skill/command that has a multi-word display name