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/notes/components/shared-view.tsx

@@ -0,0 +1,28 @@
+import { Pin } from "lucide-react";
+import type { NoteShareData } from "../server/share-queries";
+
+export function NoteSharedView({ data }: { data: NoteShareData }) {
+  const updatedAt = new Date(data.updatedAt).toLocaleDateString(undefined, {
+    year: "numeric",
+    month: "long",
+    day: "numeric",
+  });
+
+  return (
+    <div className="mx-auto max-w-xl space-y-4 p-4">
+      <header className="space-y-1">
+        {data.pinned && (
+          <span className="flex items-center gap-1 text-xs text-muted-foreground">
+            <Pin className="size-3" />
+            Pinned
+          </span>
+        )}
+        <h1 className="text-2xl font-semibold">{data.title}</h1>
+        <p className="text-xs text-muted-foreground">Updated {updatedAt}</p>
+      </header>
+      {data.body && (
+        <p className="whitespace-pre-wrap text-sm leading-relaxed">{data.body}</p>
+      )}
+    </div>
+  );
+}