fix: remove redundant update and default_options methods

Co-authored-by: aider (openai/andrew/openrouter/deepseek/deepseek-chat-v3.1) <aider@aider.chat>

src/meta_plugin/system.rs

@@ -64,13 +64,6 @@ impl MetaPlugin for CwdMetaPlugin {
         }
     }
 
-    fn update(&mut self, _data: &[u8]) -> MetaPluginResponse {
-        MetaPluginResponse {
-            metadata: Vec::new(),
-            is_finalized: false,
-        }
-    }
-
     fn meta_name(&self) -> String {
         self.meta_name.clone()
     }
@@ -109,10 +102,6 @@ impl MetaPlugin for CwdMetaPlugin {
         vec!["cwd".to_string()]
     }
     
-    fn default_options(&self) -> std::collections::HashMap<String, serde_yaml::Value> {
-        std::collections::HashMap::new()
-    }
-    
     fn options(&self) -> &std::collections::HashMap<String, serde_yaml::Value> {
         &self.options
     }