bug: read tool fails to read file that have invalid utf-8 chars

```bash
➜  forge git:(main) ✗ : check @[/Users/ranjit/.zsh_history:11975:11983]                                                                      
⏺ [17:08:35] Continue 9ec2b8d2-fbdc-41fa-81eb-3d8057381f26 [via forge/anthropic/claude-sonnet-4.5]
⏺ [17:08:35] ERROR: Failed to read file content from /Users/ranjit/.zsh_history

Caused by:
    stream did not contain valid UTF-8
```