fix: correct remaining native 'event.preventDefault()' calls

- Reverted incorrect snake_case 'event.prevent_default()' to native CamelCase 'event.preventDefault()' across multiple components.
- Finalized formatting for event files upload and archive content edit components.

src/lib/elements/element_input_file.svelte

@@ -68,7 +68,7 @@
 
     function prevent_default<T extends Event>(fn: (event: T) => void) {
         return function (event: T) {
-            event.prevent_default();
+            event.preventDefault();
             fn(event);
         };
     }

src/lib/elements/element_websocket_v2.svelte

@@ -379,7 +379,7 @@
 
     function prevent_default<T extends Event>(fn: (event: T) => void) {
         return function (event: T) {
-            event.prevent_default();
+            event.preventDefault();
             fn(event);
         };
     }