fix: remove unused MetaPlugin::binary variant

Co-authored-by: aider (openai/andrew/openrouter/mistralai/mistral-medium-3.1) <aider@aider.chat>

src/meta_plugin/mod.rs

@@ -96,7 +96,7 @@ impl MetaPlugin for BaseMetaPlugin {
     fn meta_type(&self) -> MetaPluginType {
         // This is a base implementation, so we need to return something
         // This might not be used, but we need to satisfy the trait
-        MetaPluginType::Binary
+        MetaPluginType::Text
     }
     
     fn outputs(&self) -> &std::collections::HashMap<String, serde_yaml::Value> {