feat: add assistant chatbot with eligibility auto-check

- Add ChatbotButton component to top-app-bar (bot icon, upper right)
- Slide-in chat panel with 4 options: Check Eligibility, Schedule, Claims, Chat
- Single paste area accepts member ID + DOB in either order
- Age-based routing: ≥21 → MH Eligibility & History, <21 → CMSP auto-triggered
- Insurance-status page prefills fields and auto-fires the correct button via sessionStorage + custom event

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/Frontend/src/components/layout/top-app-bar.tsx

@@ -11,6 +11,7 @@ import {
 import { Link, useLocation } from "wouter";
 import { NotificationsBell } from "@/components/layout/notification-bell";
 import { SidebarTrigger } from "@/components/ui/sidebar";
+import { ChatbotButton } from "@/components/layout/chatbot";
 
 export function TopAppBar() {
   const { user, logoutMutation } = useAuth();
@@ -53,6 +54,7 @@ export function TopAppBar() {
 
         <div className="flex items-center space-x-3">
           <NotificationsBell />
+          <ChatbotButton />
           <DropdownMenu>
             <DropdownMenuTrigger asChild>
               <Button