fix: remove saved_during_io from trait and add to BinaryMetaPlugin

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

src/meta_plugin.rs

@@ -74,7 +74,6 @@ pub trait MetaPlugin {
             value,
         };
         crate::db::store_meta(conn, meta)?;
-        self.saved_during_io = true;
         Ok(())
     }
 }

src/meta_plugin/system.rs

@@ -80,6 +80,19 @@ impl MetaPlugin for BinaryMetaPlugin {
         self.conn = Some(conn as *const _ as *mut Connection);
         Ok(())
     }
+    
+    fn save_meta(&mut self, conn: &Connection, item_id: i64, value: String) -> Result<()> {
+        let meta_name = self.meta_name();
+        debug!("Saving metadata: item_id={}, name={}, value={}", item_id, meta_name, value);
+        let meta = crate::db::Meta {
+            id: item_id,
+            name: meta_name,
+            value,
+        };
+        crate::db::store_meta(conn, meta)?;
+        self.saved_during_io = true;
+        Ok(())
+    }
 }
 
 impl CwdMetaPlugin {