[BUG] Sending files, current buffer, or lines to claude doesn't work.

## Bug Description

Sending files, current buffer, or lines to claude doesn't work.

## To Reproduce

Steps to reproduce the behavior:

1. Send files to claude code
2. See error

[ClaudeCode] [queue] [ERROR] Connection timeout - clearing 1 queued @ mentions

## Expected Behavior

I expect that files and code lines can be sent to claude. This worked for me a few days ago. I guess claude auto-updated and now it isn't working.

## Environment

- Neovim version: v0.10.4
- Claude Code CLI version: 1.0.41
- OS: macOS 15.5
- Plugin version: latest

## Error Messages
[ClaudeCode] [queue] [ERROR] Connection timeout - clearing 1 queued @ mentions

If applicable, add error messages or logs.

```
Paste any error messages here
```

## Additional Context

Add any other context about the problem here.

Reproduce the failure with Neovim v0.10.4, Claude Code CLI 1.0.41, macOS 15.5, and the latest plugin. Start from the queue handling that reports “Connection timeout” when sending files, the current buffer, or lines, and compare the behavior with the CLI versions involved. Done means those three send actions reach Claude without clearing the queued @ mentions.

索引モデルが issue の本文から書いたものです。