feat: add support for left/right alignment in list_format columns

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

src/config.rs

@@ -9,6 +9,16 @@ use crate::args::{Args};
 pub struct ColumnConfig {
     pub name: String,
     pub label: String,
+    #[serde(default)]
+    pub align: ColumnAlignment,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+#[serde(rename_all = "lowercase")]
+pub enum ColumnAlignment {
+    #[default]
+    Left,
+    Right,
 }
 
 impl<'de> serde::Deserialize<'de> for ColumnConfig {
@@ -20,6 +30,8 @@ impl<'de> serde::Deserialize<'de> for ColumnConfig {
         struct Helper {
             name: String,
             label: Option<String>,
+            #[serde(default)]
+            align: ColumnAlignment,
         }
         
         let helper = Helper::deserialize(deserializer)?;
@@ -28,6 +40,7 @@ impl<'de> serde::Deserialize<'de> for ColumnConfig {
         Ok(ColumnConfig {
             name: helper.name,
             label,
+            align: helper.align,
         })
     }
 }