fix(web): clear Design Browser caches when deleting a project

Successful DELETE already pruned tab state; also remove the per-project
history and viewport localStorage keys so browsing data does not linger.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: nmsn

apps/web/src/state/projects.ts

@@ -369,10 +369,12 @@ export async function deleteProject(id: string): Promise<boolean> {
     const resp = await fetch(`/api/projects/${encodeURIComponent(id)}`, {
       method: 'DELETE',
     });
-    // Drop the project's local tab-state cache once it is gone server-side, so
-    // the `open-design:project-tabs:*` keys don't accumulate in localStorage
-    // for the lifetime of the browser profile as projects are deleted.
-    if (resp.ok) removeCachedTabs(id);
+    // Drop per-project browser caches once the project is gone server-side so
+    // they do not accumulate in localStorage for the lifetime of the profile.
+    if (resp.ok) {
+      removeCachedTabs(id);
+      removeDesignBrowserProjectCache(id);
+    }
     return resp.ok;
   } catch {
     return false;
@@ -682,6 +684,18 @@ function removeCachedTabs(projectId: string): void {
   }
 }
 
+// Keep key shapes in sync with DesignBrowserPanel historyStorageKey /
+// viewportStorageKey. Cleared here so deleteProject does not import the panel.
+function removeDesignBrowserProjectCache(projectId: string): void {
+  if (typeof window === 'undefined') return;
+  try {
+    window.localStorage.removeItem(`od:design-browser:${projectId}:history:v1`);
+    window.localStorage.removeItem(`od:design-browser:${projectId}:viewport:v1`);
+  } catch {
+    // Ignore private-mode/quota errors; the cache entry is best-effort.
+  }
+}
+
 function writeCachedTabs(projectId: string, state: OpenTabsState): OpenTabsState {
   const next: OpenTabsState = {
     ...state,

apps/web/tests/state/projects.test.ts

@@ -462,15 +462,22 @@ describe('pickLocalFolderPath', () => {
   });
 });
 
-describe('deleteProject tabs cache', () => {
+describe('deleteProject local caches', () => {
   afterEach(() => {
     vi.unstubAllGlobals();
   });
 
   const tabsKey = 'open-design:project-tabs:v1:p1';
+  // Keep in sync with DesignBrowserPanel historyStorageKey / viewportStorageKey.
+  const historyKey = 'od:design-browser:p1:history:v1';
+  const viewportKey = 'od:design-browser:p1:viewport:v1';
 
   function stubWindowStore(): Map<string, string> {
-    const store = new Map<string, string>([[tabsKey, JSON.stringify({ tabs: [], active: null })]]);
+    const store = new Map<string, string>([
+      [tabsKey, JSON.stringify({ tabs: [], active: null })],
+      [historyKey, JSON.stringify([{ url: 'https://example.com', title: 'Example', lastVisitedAt: 1 }])],
+      [viewportKey, 'mobile'],
+    ]);
     vi.stubGlobal('window', {
       localStorage: {
         getItem: (k: string) => store.get(k) ?? null,
@@ -485,17 +492,21 @@ describe('deleteProject tabs cache', () => {
     return store;
   }
 
-  it('prunes the project tabs cache on a successful delete', async () => {
+  it('prunes tabs and Design Browser caches on a successful delete', async () => {
     const store = stubWindowStore();
     vi.stubGlobal('fetch', vi.fn<typeof fetch>(async () => new Response(null, { status: 200 })));
     await expect(deleteProject('p1')).resolves.toBe(true);
     expect(store.has(tabsKey)).toBe(false);
+    expect(store.has(historyKey)).toBe(false);
+    expect(store.has(viewportKey)).toBe(false);
   });
 
-  it('keeps the tabs cache when the delete fails', async () => {
+  it('keeps tabs and Design Browser caches when the delete fails', async () => {
     const store = stubWindowStore();
     vi.stubGlobal('fetch', vi.fn<typeof fetch>(async () => new Response(null, { status: 500 })));
     await expect(deleteProject('p1')).resolves.toBe(false);
     expect(store.has(tabsKey)).toBe(true);
+    expect(store.has(historyKey)).toBe(true);
+    expect(store.has(viewportKey)).toBe(true);
   });
 });