feat: release contextual omnichannel customer platform

Add Telegram, WhatsApp and email account management, realtime messaging, contextual multilingual AI, customer intelligence, knowledge workflows, enterprise controls, a unified design system and complete repository documentation.

src/components/layout/AppLayout.tsx

@@ -9,7 +9,7 @@ export function AppLayout() {
   const { mobileNavOpen, setMobileNavOpen } = useUiStore()
 
   return (
-    <div className="flex h-screen overflow-hidden bg-background">
+    <div className="flex h-screen overflow-hidden bg-[#f7f9fc]">
       <GlobalRealtime />
       {/* 桌面端固定侧边栏 */}
       <div className="hidden shrink-0 lg:block">
@@ -25,7 +25,7 @@ export function AppLayout() {
 
       <div className="flex min-w-0 flex-1 flex-col">
         <Topbar />
-        <main className="flex-1 overflow-y-auto bg-white/35 scrollbar-thin" id="main-scroll">
+        <main className="flex-1 overflow-y-auto bg-[#f7f9fc] scrollbar-thin" id="main-scroll">
           <Outlet />
         </main>
       </div>