Implement share viewer (task 31)

- Makes actorId nullable in activity_log (migration 0010) with onDelete:
  set null so audit history survives user deletion; adds logShareActivity
  for anonymous mutations
- Adds resolveShareToken return of householdId for downstream validation
- Adds renderSharedView to EntityTypeRegistration; each module implements
  loadForShare (no-session bare queries) and renderSharedView
- Calendar: CalendarSharedView (upcoming 90-day events) and
  EventSharedView (title/time/location/notes)
- Lists: ListSharedView (client component with optimistic toggles via
  toggleShareListItem server action in lists/server/share-actions.ts)
- Notes: NoteSharedView (title + body + updated date)
- /app/s/[token]/page.tsx: resolves token, dispatches to loadForShare +
  renderSharedView, friendly error for invalid/expired tokens, noindex
- Middleware /s/* exemption confirmed present (no change needed)

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

src/modules/lists/components/shared-view.tsx

@@ -0,0 +1,104 @@
+"use client";
+
+import { useOptimistic, useTransition } from "react";
+import type { ListShareData, ListShareItem } from "../server/share-queries";
+import { toggleShareListItem } from "../server/share-actions";
+
+export function ListSharedView({
+  data,
+  canWrite,
+  token,
+}: {
+  data: ListShareData;
+  canWrite: boolean;
+  token: string;
+}) {
+  const [optimisticItems, setOptimisticItems] = useOptimistic(
+    data.items,
+    (current: ListShareItem[], { id, done }: { id: string; done: boolean }) =>
+      current.map((item) => (item.id === id ? { ...item, done } : item)),
+  );
+  const [, startTransition] = useTransition();
+
+  function toggle(item: ListShareItem) {
+    if (!canWrite) return;
+    const next = !item.done;
+    startTransition(async () => {
+      setOptimisticItems({ id: item.id, done: next });
+      await toggleShareListItem(token, item.id);
+    });
+  }
+
+  const open = optimisticItems.filter((i) => !i.done);
+  const done = optimisticItems.filter((i) => i.done);
+
+  return (
+    <div className="mx-auto max-w-xl space-y-4 p-4">
+      <header>
+        <h1 className="text-2xl font-semibold">{data.name}</h1>
+        <p className="text-sm text-muted-foreground capitalize">{data.type}</p>
+      </header>
+
+      {optimisticItems.length === 0 ? (
+        <p className="text-sm text-muted-foreground">This list is empty.</p>
+      ) : (
+        <div className="space-y-4">
+          {open.length > 0 && (
+            <ul className="divide-y rounded-lg border bg-background">
+              {open.map((item) => (
+                <ItemRow key={item.id} item={item} canWrite={canWrite} onToggle={toggle} />
+              ))}
+            </ul>
+          )}
+          {done.length > 0 && (
+            <details className="group">
+              <summary className="cursor-pointer select-none text-sm text-muted-foreground">
+                {done.length} completed
+              </summary>
+              <ul className="mt-2 divide-y rounded-lg border bg-background">
+                {done.map((item) => (
+                  <ItemRow key={item.id} item={item} canWrite={canWrite} onToggle={toggle} />
+                ))}
+              </ul>
+            </details>
+          )}
+        </div>
+      )}
+    </div>
+  );
+}
+
+function ItemRow({
+  item,
+  canWrite,
+  onToggle,
+}: {
+  item: ListShareItem;
+  canWrite: boolean;
+  onToggle: (item: ListShareItem) => void;
+}) {
+  return (
+    <li className="flex items-center gap-3 px-4 py-3">
+      {canWrite ? (
+        <input
+          type="checkbox"
+          aria-label={`Complete ${item.text}`}
+          className="size-5 accent-primary"
+          checked={item.done}
+          onChange={() => onToggle(item)}
+        />
+      ) : (
+        <span
+          aria-hidden
+          className={`size-5 shrink-0 rounded-sm border border-border ${item.done ? "bg-muted" : ""}`}
+        />
+      )}
+      <span className={`text-sm ${item.done ? "text-muted-foreground line-through" : ""}`}>
+        {item.text}
+        {item.qty && (
+          <span className="ml-1 text-xs text-muted-foreground">×{item.qty}</span>
+        )}
+      </span>
+    </li>
+  );
+}