feat(user-perf): add ui user-perf + dotfile filter

- add resource kind filter (file, folder, drive) in shared section (localStorage stored)
- add user preferences serverside store
- add client side dotfile filter (show/hide dotfiles) (user perf stored, default: dotfiles are shown)
  for security trashed dotfile are always displayed

  protection added: if a folder has only hidden items, a notification invite user to display it
  if a user rename or create a hidden item, a notification tells it to user

frontend/src/routes/trash/+page.svelte

@@ -30,6 +30,13 @@
 	let groupBy = $state('remainingDays');
 	let reversed = $state(false);
 
+	// Trash view DELIBERATELY ignores `preferences.hideDotfiles`.
+	// Rationale: trash is a safety net — hiding items here would let
+	// an accidentally-trashed dotfile ride the retention timer to
+	// permanent deletion without ever being visible for recovery.
+	// The hide preference is UI cosmetics elsewhere; here it would
+	// become a footgun. Same reasoning applies to any future
+	// "review before destructive action" surface.
 	const entries = $derived(
 		raw.map((it): ResourceEntry => {
 			const isFile = it.resource_type === 'file';