feat: implement unified settings system

Co-authored-by: aider (openai/andrew/openrouter/anthropic/claude-sonnet-4) <aider@aider.chat>

src/modes/common.rs

@@ -157,12 +157,6 @@ impl FromStr for OutputFormat {
     }
 }
 
-pub fn get_output_format(args: &Args) -> OutputFormat {
-    args.options.output_format
-        .as_ref()
-        .and_then(|s| OutputFormat::from_str(s).ok())
-        .unwrap_or(OutputFormat::Table)
-}
 
 pub fn cmd_args_meta_plugin_types(cmd: &mut Command, args: &Args) -> Vec<MetaPluginType> {
     let mut meta_plugin_types = Vec::new();
@@ -200,3 +194,83 @@ pub fn cmd_args_meta_plugin_types(cmd: &mut Command, args: &Args) -> Vec<MetaPlu
 
     meta_plugin_types
 }
+
+pub fn settings_meta_plugin_types(cmd: &mut Command, settings: &crate::config::Settings) -> Vec<MetaPluginType> {
+    let mut meta_plugin_types = Vec::new();
+    
+    // Handle comma-separated values in each meta_plugins argument
+    for meta_plugin_names_str in &settings.meta_plugins {
+        let meta_plugin_names: Vec<&str> = meta_plugin_names_str.split(',').collect();
+        
+        for name in meta_plugin_names {
+            let trimmed_name = name.trim();
+            if trimmed_name.is_empty() {
+                continue;
+            }
+            
+            // Try to find the MetaPluginType by meta name
+            let mut found = false;
+            for meta_plugin_type in MetaPluginType::iter() {
+                let mut meta_plugin = crate::meta_plugin::get_meta_plugin(meta_plugin_type.clone());
+                if meta_plugin.meta_name() == trimmed_name {
+                    meta_plugin_types.push(meta_plugin_type);
+                    found = true;
+                    break;
+                }
+            }
+            
+            if !found {
+                cmd.error(
+                    ErrorKind::InvalidValue,
+                    format!("Unknown meta plugin type: {}", trimmed_name),
+                )
+                .exit();
+            }
+        }
+    }
+
+    meta_plugin_types
+}
+
+pub fn settings_digest_type(cmd: &mut Command, settings: &crate::config::Settings) -> MetaPluginType {
+    let digest_name = settings
+        .digest
+        .clone()
+        .unwrap_or(MetaPluginType::DigestSha256.to_string());
+
+    let digest_type_opt = MetaPluginType::from_str(&digest_name);
+    if digest_type_opt.is_err() {
+        cmd.error(
+            ErrorKind::InvalidValue,
+            format!("Invalid digest algorithm '{}'. Use 'sha256' or 'md5'", digest_name),
+        )
+        .exit();
+    }
+
+    digest_type_opt.unwrap()
+}
+
+pub fn settings_compression_type(cmd: &mut Command, settings: &crate::config::Settings) -> CompressionType {
+    let compression_name = settings
+        .compression
+        .clone()
+        .unwrap_or(CompressionType::LZ4.to_string());
+
+    let compression_type_opt = CompressionType::from_str(&compression_name);
+    if compression_type_opt.is_err() {
+        cmd.error(
+            ErrorKind::InvalidValue,
+            format!("Invalid compression algorithm '{}'. Supported algorithms: lz4, gzip, xz, zstd", compression_name),
+        )
+        .exit();
+    }
+
+    compression_type_opt.unwrap()
+}
+
+pub fn settings_output_format(settings: &crate::config::Settings) -> OutputFormat {
+    settings.output_format
+        .as_ref()
+        .and_then(|s| OutputFormat::from_str(s).ok())
+        .unwrap_or(OutputFormat::Table)
+}