feat: add support for meta plugin options and outputs

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

src/config.rs

@@ -62,6 +62,10 @@ pub struct CompressionPluginConfig {
 #[derive(Debug, Clone, Deserialize, Serialize)]
 pub struct MetaPluginConfig {
     pub name: String,
+    #[serde(default)]
+    pub options: std::collections::HashMap<String, serde_yaml::Value>,
+    #[serde(default)]
+    pub outputs: std::collections::HashMap<String, String>,
 }
 
 /// Unified settings that merges config file and CLI arguments