[BUG] New agent view functionality breaks send to CC

## Bug Description

When using the the new agents view mode, selecting text to send to Claude doesn't result in anything being sent to it. Also, the current file information doesn't get passed through to it either.

## To Reproduce

Steps to reproduce the behavior:

1. Open an agent from the agent view
2. Select text and try to send it to claude code (as)
3. Nothing happens

## Expected Behavior

Claude should receive the filename and line number

## Environment

- Neovim version: 11.6
- Claude Code CLI version: 2.1.140
- OS: Tahoe 26.4.1
- Plugin version: commit 102d835

## Error Messages
None

If applicable, add error messages or logs.

```
Paste any error messages here
```

## Additional Context

Add any other context about the problem here.

Start by reproducing the failure in the agent view, then trace the agent-view selection and send-to-Claude path and compare it with the working view. Confirm that selected text is sent and that Claude receives the current filename and line number.

Written by the indexing model from the issue text.