feat: live updates on shared meal plans

Two separate components (the owner's own week view and collaborators'
shared view) hit two different API surfaces for the same underlying
entries, so neither ever saw the other's edits without a manual
reload. Both now poll a new lean GET on their respective entries
routes every 4s, merged with the same dirty-until-ref guard used for
shopping lists so a poll can't stomp an in-flight local edit.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/app/api/v1/meal-plans/shared/[mealPlanId]/entries/route.ts

@@ -7,6 +7,33 @@ import { dispatchWebhook } from "@/lib/webhooks";
 
 type Params = { params: Promise<{ mealPlanId: string }> };
 
+// Polled by SharedMealPlanView so every collaborator sees each other's
+// changes, and the plan owner's own tab (a different component/URL, per
+// meal-plans/[weekStart]/entries) picks up edits made from here too.
+export async function GET(_req: NextRequest, { params }: Params) {
+  const { session, response } = await requireSession();
+  if (response) return response;
+  const { mealPlanId } = await params;
+
+  const access = await getMealPlanAccessById(mealPlanId, session!.user.id);
+  if (!access) return NextResponse.json({ error: "Not found" }, { status: 404 });
+
+  const entries = await db.query.mealPlanEntries.findMany({
+    where: eq(mealPlanEntries.mealPlanId, mealPlanId),
+    with: { recipe: { columns: { id: true, title: true } } },
+  });
+
+  return NextResponse.json({
+    entries: entries.map((e) => ({
+      id: e.id,
+      day: e.day,
+      mealType: e.mealType,
+      servings: e.servings,
+      recipe: e.recipe,
+    })),
+  });
+}
+
 const Schema = z.object({
   day: z.enum(["mon", "tue", "wed", "thu", "fri", "sat", "sun"]),
   mealType: z.enum(["breakfast", "lunch", "dinner", "snack"]),