Can export family data

geneit_backend/src/models.rs

@@ -168,6 +168,13 @@ impl Photo {
     pub fn thumbnail_path(&self) -> String {
         format!("thumbnail/{}", self.file_id)
     }
+
+    pub fn mime_extension(&self) -> Option<&str> {
+        mime_guess::get_mime_extensions_str(&self.mime_type)
+            .map(|e| e.first())
+            .unwrap_or_default()
+            .copied()
+    }
 }
 
 #[derive(Insertable)]