feat: 类型帖互动、积分经济与发帖体验

补齐问答采纳/重开、投票匿名与有票禁编、悬赏过期退回、抽奖回帖开奖，并接入积分账本与发帖附件可见性。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/app/layout.tsx

@@ -5,6 +5,7 @@ import "./globals.css";
 import Header from "@/components/Header";
 import Footer from "@/components/Footer";
 import Toaster from "@/components/Toaster";
+import TipHost from "@/components/TipHost";
 import AccountGuard from "@/components/AccountGuard";
 import ThemeSync from "@/components/ThemeSync";
 import RealtimeProvider from "@/components/RealtimeProvider";
@@ -112,6 +113,7 @@ export default async function RootLayout({
         </main>
         <Footer />
         <Toaster />
+        <TipHost />
         <AccountGuard />
         <ThemeSync initialAccent={accent || ""} />
         <RealtimeProvider userId={user ? user.id : null} />