[bug]: Edge Stones not being captured

### Describe the bug


Edge stones are not being captured like corner stones or middle stones are.

### Steps to reproduce

1. Run the game
2. place a victim single stone at any of the edges, but not corners
3. place opponent stones around to capture said victim stone
4. Find the bug

### Expected behavior

The victim stone should be captured.

### Additional information

_No response_

### Operating system

Linux

Start by running the game on Linux and reproduce the issue using the listed steps: place a single stone on a non-corner edge, then surround it with opponent stones. Trace the capture handling for edge positions and compare it with corner and middle stones; done means the edge victim stone is captured as expected. An open linked pull request (#18) indicates that work is already underway.

Written by the indexing model from the issue text.