Slash command picker only activates at start of input, despite v2.1.0 changelog claiming "anywhere in input" support

Summary

The slash command picker dropdown only appears when / is at the very
beginning of the input line (position 0). When / is typed after any
leading text, the picker never shows — only the first-position /
triggers it.

This contradicts the v2.1.0 changelog entry:

Added slash command autocomplete support when / appears anywhere in input, not just at the beginning

Environment

• Claude Code version: 2.1.126
• OS: macOS
• Terminal: Terminal.app

Steps to reproduce

1. Open Claude Code interactive session
2. Type a slash command first, then some text, then another slash:

/review this PR /commit

1. The picker appears for /review at position 0
2. After typing this PR, type /commit
3. Expected: picker dropdown appears showing matching commands
4. Actual: nothing happens — no picker, no suggestions

Variants tested

| Input | Picker appears? | Notes |
|-----------------------------|-----------------|--------------------------------|
| /cmd | Yes | Position 0 — works |
| /cmd /cmd2 | Yes (both) | Consecutive, no text in between |
| text /cmd | Yes | Whitespace before / |
| /cmd text /cmd2 | No | After leading cmd + text |
| /cmd --arg text /cmd2 | No | After leading cmd with args |

The pattern: the picker works when / follows whitespace at position 0
or immediately after another slash command. It fails when / comes after
any non-command text, even when preceded by whitespace.

Why this matters

Users often chain commands in natural language:

/compact the context and then /security-review

Or compose multi-step workflows:

/review this PR and also /commit

The picker not appearing breaks the flow — the user must delete back to
the start, invoke the picker, then retype everything. The @ file
autocomplete works mid-text without this limitation.

Related

• Issue #9750 (feature request for inline autocomplete, closed "not planned")
• The v2.1.0 changelog entry that suggests this should already work

Suggested fix

Extend the picker trigger logic beyond position 0. When the user types
/ preceded by whitespace anywhere in the input, activate the slash
command picker — matching the behavior of @ file autocomplete which
already handles mid-text positions.