fix: Handle ColumnAlignment::Center in server pages

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

src/modes/server/pages.rs

@@ -222,6 +222,7 @@ fn build_item_list(conn: &Connection, params: &ListQueryParams, columns: &[Colum
             let align_style = match column.align {
                 crate::config::ColumnAlignment::Left => "text-align: left;",
                 crate::config::ColumnAlignment::Right => "text-align: right;",
+                crate::config::ColumnAlignment::Center => "text-align: center;",
             };
             
             html.push_str(&format!("<td style=\"{}\">{}</td>", align_style, display_value));