fix: remove unused imports and fix test stdin handling

Co-authored-by: aider (openai/andrew.openrouter.qwen.qwen3-coder) <aider@aider.chat>

src/tests.rs

@@ -17,8 +17,10 @@ mod tests {
         cmd.args(args)
             .env("KEEP_DIR", keep_dir);
         
-        if let Some(_data) = stdin_data {
+        if stdin_data.is_some() {
             cmd.stdin(std::process::Stdio::piped());
+        } else {
+            cmd.stdin(std::process::Stdio::null());
         }
         
         let mut child = cmd.spawn().expect("Failed to execute keep command");