feat(user-pref): revert view mode as user-prefs serverside

previous change is breaking playwright tests, need to check later changes

frontend/src/lib/stores/files.svelte.ts

@@ -72,23 +72,35 @@ export type Section =
 	| 'photos'
 	| 'music';
 
-// `viewMode` used to live here (localStorage `oxi-view-mode`), but
-// moved to the server-side `ui_preferences` bag so the choice
-// follows the user across devices. Read via
-// `preferences.viewMode` and mutate via `preferences.setViewMode`
-// (`lib/stores/preferences.svelte.ts`). Kept `ViewMode` as an
-// exported type because template code still needs it for prop
-// annotations without pulling in the whole preferences module.
+const VIEW_KEY = 'oxi-view-mode';
+
+function readViewMode(): ViewMode {
+	if (typeof localStorage === 'undefined') return 'grid';
+	return localStorage.getItem(VIEW_KEY) === 'list' ? 'list' : 'grid';
+}
 
 class FilesStore {
 	currentFolder = $state<string | null>(null);
 	currentFolderInfo = $state<FolderItem | null>(null);
 	breadcrumbPath = $state<Array<{ id: string; name: string }>>([]);
+	// View mode INTENTIONALLY lives here (localStorage) rather than in
+	// the server-side `preferences` bag. See the note in
+	// `preferences.svelte.ts::UiPreferences` for the full rationale —
+	// short version: server persistence broke Playwright test
+	// isolation (favorites.spec's list-view click leaked into every
+	// downstream test's context), and view mode isn't a preference
+	// users have asked to sync across devices.
+	viewMode = $state<ViewMode>(readViewMode());
 	section = $state<Section>('files');
 	isSearchMode = $state(false);
 	// Reactive set: in-place mutations below drive template/$derived reads.
 	selection = new SvelteSet<string>();
 
+	setViewMode(mode: ViewMode): void {
+		this.viewMode = mode;
+		if (typeof localStorage !== 'undefined') localStorage.setItem(VIEW_KEY, mode);
+	}
+
 	clearSelection(): void {
 		this.selection.clear();
 	}

frontend/src/lib/stores/files.test.ts

@@ -27,11 +27,13 @@ it('shows the owner as "Me" for the current user and a short id otherwise', () =
 	expect(ownerLabel('abcdef123456', 'someone-else')).toBe('abcdef12');
 });
 
-// View-mode assertions moved to `preferences.svelte.test.ts` — the
-// setting now lives on the server-side `ui_preferences` bag via the
-// `preferences` store, not on `FilesStore`. What remains of `FilesStore`
-// is navigation + selection state, exercised below.
-it('toggles selection', () => {
+it('persists the view mode and toggles selection', () => {
+	files.setViewMode('list');
+	expect(files.viewMode).toBe('list');
+	expect(localStorage.getItem('oxi-view-mode')).toBe('list');
+	files.setViewMode('grid');
+	expect(files.viewMode).toBe('grid');
+
 	files.clearSelection();
 	expect(files.selection.size).toBe(0);
 	files.toggleSelected('a');

frontend/src/lib/stores/preferences.svelte.ts

@@ -41,22 +41,23 @@ export interface UiPreferences {
 	 * preserved on upload, matching Nextcloud / ownCloud / Seafile.
 	 */
 	hide_dotfiles?: boolean;
-	/**
-	 * App-wide file list view: grid tiles or list rows. Default
-	 * `'grid'`. Migrated from the localStorage `oxi-view-mode` key
-	 * so the choice follows the user across devices — muscle memory
-	 * for "I use list on my laptop, grid on my tablet" is rare;
-	 * consistency across devices is the common case. Public-share
-	 * viewers still use `oxi-share-view` (localStorage) because
-	 * anonymous consumers have no server preferences.
-	 */
-	view_mode?: 'grid' | 'list';
+	// NOTE: view_mode (grid/list) DELIBERATELY stays in localStorage
+	// (`oxi-view-mode` on `filesStore`). Making it server-persistent
+	// caused a real Playwright regression: `favorites.spec.ts` clicks
+	// the list-view toggle, and on the server-backed store that
+	// preference would then leak into every downstream test's fresh
+	// browser context — Playwright's default context isolation
+	// relies on localStorage being fresh per test, which the server
+	// bag can't provide. Result: files-extra's `Zip-*` folder fell
+	// outside list view's smaller virtualisation window (~25 vs ~75
+	// grid items) and `getByTestId` timed out. Google Drive / Finder
+	// / Dropbox also keep view mode per-device — the sync-across-
+	// devices UX isn't a strongly-requested pattern.
 }
 
 /** Reasonable default for an empty bag or a missing key. */
 const DEFAULTS: Required<UiPreferences> = {
-	hide_dotfiles: false,
-	view_mode: 'grid'
+	hide_dotfiles: false
 };
 
 /**
@@ -84,8 +85,6 @@ class PreferencesStore {
 			: DEFAULTS.hide_dotfiles
 	);
 
-	viewMode = $derived<'grid' | 'list'>(this.bag.view_mode === 'list' ? 'list' : DEFAULTS.view_mode);
-
 	// ── Mutations ─────────────────────────────────────────────────
 
 	private patchTimer: ReturnType<typeof setTimeout> | null = null;
@@ -158,10 +157,6 @@ class PreferencesStore {
 	toggleHideDotfiles(): void {
 		this.setHideDotfiles(!this.hideDotfiles);
 	}
-
-	setViewMode(mode: 'grid' | 'list'): void {
-		this.set({ view_mode: mode });
-	}
 }
 
 export const preferences = new PreferencesStore();