refactor: remove is_default from meta plugins and add read_time/read_rate plugins

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

src/meta_plugin/digest.rs

@@ -40,9 +40,6 @@ impl MetaPlugin for DigestSha256MetaPlugin {
         self.meta_name.clone()
     }
 
-    fn is_default(&self) -> bool {
-        true
-    }
 }
 
 // Dummy writer that implements Write but doesn't do anything

src/meta_plugin/program.rs

@@ -16,12 +16,12 @@ pub struct MetaPluginProgram {
     pub args: Vec<String>,
     pub supported: bool,
     pub meta_name: String,
-    pub is_default: bool,
+    pub split_whitespace: bool,
     buffer: Vec<u8>,
 }
 
 impl MetaPluginProgram {
-    pub fn new(program: &str, args: Vec<&str>, meta_name: String, is_default: bool) -> MetaPluginProgram {
+    pub fn new(program: &str, args: Vec<&str>, meta_name: String, split_whitespace: bool) -> MetaPluginProgram {
         let program_path = get_program_path(program);
         let supported = program_path.is_ok();
 
@@ -30,7 +30,7 @@ impl MetaPluginProgram {
             args: args.iter().map(|s| s.to_string()).collect(),
             supported,
             meta_name,
-            is_default,
+            split_whitespace,
             buffer: Vec::new(),
         }
     }
@@ -90,8 +90,8 @@ impl MetaPlugin for MetaPluginProgram {
             let stdout = String::from_utf8_lossy(&output.stdout);
             let trimmed_result = stdout.trim();
             
-            // For certain programs like md5sum, we only want the first part before whitespace
-            if self.program.ends_with("sum") {
+            // For certain programs, we only want the first part before whitespace
+            if self.split_whitespace {
                 let parts: Vec<&str> = trimmed_result.split_whitespace().collect();
                 if !parts.is_empty() {
                     Ok(parts[0].to_string())
@@ -118,9 +118,6 @@ impl MetaPlugin for MetaPluginProgram {
         self.meta_name.clone()
     }
 
-    fn is_default(&self) -> bool {
-        self.is_default
-    }
 }
 
 fn get_program_path(program: &str) -> Result<String> {