fix: split md5sum output on whitespace to extract only the hash value

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

src/meta_plugin/program.rs

@@ -88,7 +88,19 @@ impl MetaPlugin for MetaPluginProgram {
 
         if output.status.success() {
             let stdout = String::from_utf8_lossy(&output.stdout);
-            Ok(stdout.trim().to_string())
+            let trimmed_result = stdout.trim();
+            
+            // For certain programs like md5sum, we only want the first part before whitespace
+            if self.program.ends_with("sum") {
+                let parts: Vec<&str> = trimmed_result.split_whitespace().collect();
+                if !parts.is_empty() {
+                    Ok(parts[0].to_string())
+                } else {
+                    Ok(trimmed_result.to_string())
+                }
+            } else {
+                Ok(trimmed_result.to_string())
+            }
         } else {
             let stderr = String::from_utf8_lossy(&output.stderr);
             Err(io::Error::new(