[BUG] split in another tab

## Bug Description

When claude code tries to edit file that is not the current active one, it is often (always?) open it in new tab and switches to it , losing claudecode ui.

This happens
```
set splitbelow
set splitright
```
probably because of these settings^^

## To Reproduce

configure the settings.
open file. ask claude to edit another file.

## Expected Behavior

All should be in the same window
## Environment

- Neovim version: [e.g. 0.9.2] 11.0.05
- Claude Code CLI version: [e.g. 1.0.0] doesn't matter
- OS: [e.g. macOS 14.1] windows 10
- Plugin version: [e.g. 0.1.0] last commit ac2baef

No source file or test is named. First reproduce the issue in Neovim with `set splitbelow` and `set splitright`, then trace the plugin's handling when Claude Code edits a non-active file. Done means editing another file keeps the Claude Code UI in the same window and adds regression coverage if the repository has an existing test location.

Written by the indexing model from the issue text.