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/_core/share.ts

@@ -61,7 +61,12 @@ export async function createShareLink(
 
 export async function resolveShareToken(
   rawToken: string,
-): Promise<{ entityType: string; entityId: string; capabilities: ShareLinkCapabilities } | null> {
+): Promise<{
+  entityType: string;
+  entityId: string;
+  capabilities: ShareLinkCapabilities;
+  householdId: string;
+} | null> {
   const tokenHash = hashToken(rawToken);
 
   const [link] = await db
@@ -78,6 +83,7 @@ export async function resolveShareToken(
     entityType: link.entityType,
     entityId: link.entityId,
     capabilities: link.capabilities,
+    householdId: link.householdId,
   };
 }