Implement quick-add registry (task 21)

- Add url field to QuickAddAction; make action optional
- Add getQuickAdds() + SerializedQuickAddItem to registry so quick-add
  data can cross the server→client RSC boundary without serializing fns
- Update calendar/lists/notes manifests with navigation URLs
- QuickAddProvider wraps root layout: holds sheet/palette open state and
  global cmd/ctrl+k shortcut
- QuickAddSheet: bottom drawer on mobile, right-side popover on desktop,
  actions grouped by module
- CommandPalette: cmdk-powered modal with fuzzy filter and full keyboard
  nav (arrows + enter + esc)
- QuickAddFab: client button replacing the plain + stub in the dashboard
- Add .claude/** to ESLint ignores to prevent stale worktree artifacts
  from failing lint

All 4 E2E specs pass; typecheck, lint, and build clean.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/modules/lists/manifest.tsx

@@ -1,6 +1,5 @@
 import type { ModuleManifest, WidgetContext } from "../_core/module";
 import { z } from "zod";
-import { addItemToDefaultList } from "./server/actions";
 import { listLists, listWidgetItems, searchItems, searchLists } from "./server/queries";
 
 const listIdsSchema = z.union([z.literal("all"), z.array(z.string().uuid())]);
@@ -90,23 +89,19 @@ const manifest: ModuleManifest = {
       id: "lists.add-shopping",
       label: "Add to shopping",
       icon: "shopping-cart",
-      action: async () => {
-        await addItemToDefaultList({ type: "shopping", text: "New item" });
-      },
+      url: "/lists",
     },
     {
       id: "lists.add-task",
       label: "Add to tasks",
       icon: "list-checks",
-      action: async () => {
-        await addItemToDefaultList({ type: "task", text: "New task" });
-      },
+      url: "/lists",
     },
     {
       id: "lists.new-list",
       label: "New list",
       icon: "list-plus",
-      action: () => undefined,
+      url: "/lists",
     },
   ],
 };