refactor: remove dead code identified by knip

Delete unused Fab component (superseded by QuickAddFab), unused server
actions and queries (listDashboards, reorderDashboards, deleteCareLog,
canAccessContainer, getOverduePlants, getCareDueSoon, addItemToDefaultList,
reorderItems, getOrCreateDefaultList), unused helpers (getCurrentUser,
BrandWordmark, TopbarSpacer, DEV_LOGIN_COOKIE, no-arg ensureDefault*
wrappers, addListItem re-export), and drop export keyword from five
internal-only functions.

Verified with typecheck, eslint, and production build after each removal.

src/modules/lists/server/actions.ts

@@ -8,7 +8,6 @@ import { getCurrentSession } from "@/lib/session";
 import { logActivity } from "@/modules/_core/activity";
 import { fireItemToggleHooks } from "@/modules/_core/registry";
 import { listItems, lists } from "../schema";
-import { getOrCreateDefaultList } from "./defaults";
 import { canAccessList, getList } from "./queries";
 import { notifyListChanged } from "./realtime";
 
@@ -122,18 +121,6 @@ export async function addItem(input: z.input<typeof itemInput>) {
   return getList(parsed.listId);
 }
 
-export async function addItemToDefaultList(input: { type: string; text: string }) {
-  const parsed = z
-    .object({
-      type: listInput.shape.type,
-      text: itemInput.shape.text,
-    })
-    .parse(input);
-  const { household } = await getCurrentSession();
-  const list = await getOrCreateDefaultList({ householdId: household.id, type: parsed.type });
-  return addItem({ listId: list.id, text: parsed.text });
-}
-
 export async function toggleItem(input: { id: string; done?: boolean }) {
   const parsed = z.object({ id: z.string().uuid(), done: z.boolean().optional() }).parse(input);
   const { household, user } = await getCurrentSession();