fix: implement debug for meta plugin program and remove unused imports

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

src/meta_plugin/program.rs

@@ -7,7 +7,6 @@ use which::which;
 
 use crate::meta_plugin::MetaPlugin;
 
-#[derive(Debug)]
 pub struct MetaPluginProgram {
     pub program: String,
     pub args: Vec<String>,
@@ -18,6 +17,20 @@ pub struct MetaPluginProgram {
     writer: Option<Box<dyn Write>>,
 }
 
+impl std::fmt::Debug for MetaPluginProgram {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("MetaPluginProgram")
+            .field("program", &self.program)
+            .field("args", &self.args)
+            .field("supported", &self.supported)
+            .field("meta_name", &self.meta_name)
+            .field("split_whitespace", &self.split_whitespace)
+            .field("process", &self.process)
+            .field("writer", &"Box<dyn Write>")
+            .finish()
+    }
+}
+
 impl MetaPluginProgram {
     pub fn new(program: &str, args: Vec<&str>, meta_name: String, split_whitespace: bool) -> MetaPluginProgram {
         let program_path = which(program);
@@ -77,7 +90,7 @@ impl MetaPlugin for MetaPluginProgram {
         // Close stdin to signal EOF to the process
         self.writer.take();
 
-        if let Some(mut process) = self.process.take() {
+        if let Some(process) = self.process.take() {
             let output = process.wait_with_output()
                 .map_err(|e| io::Error::new(io::ErrorKind::Other, format!("Failed to wait for process: {}", e)))?;