feat: chat window, preferred language, insurance contact, and AI call eligibility

- Schedule: right-click Chat option opens floating SMS chat window
- Chat window: SMS template selector with appointment date/time pre-filled
- Chat window: office name and phone pulled from Settings > Office Contact
- Chat window: Preferred Language selector (English, Spanish, Portuguese,
  Mandarin, Cantonese, Arabic, Haitian Creole) with fully translated templates
  and locale-aware date/time formatting
- Patient form: Preferred Language field (add/edit), default English
- Settings > Office Contact: added Dental Office Name field
- Settings > Advanced: Insurance Contact page (CRUD — company name + phone)
- Prisma schema: preferredLanguage on Patient, officeName on OfficeContact,
  new InsuranceContact model
- Patient management: Upload Patient Document moved below Patient Records
- Insurance Eligibility: AI Call Insurance collapsible section; insurance
  company and phone auto-populated from saved Insurance Contacts

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

apps/Frontend/src/pages/appointments-page.tsx

@@ -26,6 +26,7 @@ import {
   LoaderCircleIcon,
   Stethoscope,
   Download,
+  MessageSquare,
 } from "lucide-react";
 import { useToast } from "@/hooks/use-toast";
 import { Calendar } from "@/components/ui/calendar";
@@ -60,6 +61,7 @@ import {
 import { SeleniumTaskBanner } from "@/components/ui/selenium-task-banner";
 import { PatientStatusBadge } from "@/components/appointments/patient-status-badge";
 import type { OfficeHoursData } from "@/components/settings/office-hours-card";
+import { MessageThread } from "@/components/patient-connection/message-thread";
 
 // Define types for scheduling
 interface TimeSlot {
@@ -201,6 +203,10 @@ export default function AppointmentsPage() {
   const [selectProceduresPatientId, setSelectProceduresPatientId] = useState<number | null>(null);
   const [selectProceduresAppointmentId, setSelectProceduresAppointmentId] = useState<number | null>(null);
 
+  // Chat popup state
+  const [chatPatient, setChatPatient] = useState<Patient | null>(null);
+  const [chatAppointmentInfo, setChatAppointmentInfo] = useState<{ date: string; startTime: string } | undefined>(undefined);
+
   // Create context menu hook
   const { show } = useContextMenu({
     id: APPOINTMENT_CONTEXT_MENU_ID,
@@ -756,6 +762,24 @@ export default function AppointmentsPage() {
     });
   };
 
+  // Open chat window for the patient linked to this appointment
+  const handleChat = (appointmentId: number) => {
+    const apt = appointments.find((a) => a.id === appointmentId);
+    if (!apt) return;
+    const patient = patientsFromDay.find((p) => p.id === (apt as any).patientId);
+    if (!patient) return;
+    const processed = processedAppointments.find((a) => a.id === appointmentId);
+    setChatPatient(patient as Patient);
+    if (processed) {
+      setChatAppointmentInfo({
+        date: typeof processed.date === "string" ? processed.date : formatLocalDate(processed.date as Date),
+        startTime: typeof processed.startTime === "string" ? processed.startTime.substring(0, 5) : "",
+      });
+    } else {
+      setChatAppointmentInfo(undefined);
+    }
+  };
+
   // Function to display context menu
   const handleContextMenu = (e: React.MouseEvent, appointmentId: number) => {
     // Prevent the default browser context menu
@@ -1478,6 +1502,14 @@ export default function AppointmentsPage() {
               Claim Status
             </span>
           </Item>
+
+          {/* Chat */}
+          <Item onClick={({ props }) => handleChat(props.appointmentId)}>
+            <span className="flex items-center gap-2 text-blue-600">
+              <MessageSquare className="h-4 w-4" />
+              Chat
+            </span>
+          </Item>
         </Menu>
 
         {/* Main Content  */}
@@ -1688,6 +1720,19 @@ export default function AppointmentsPage() {
         </div>
       )}
 
+      {/* Chat popup */}
+      {chatPatient && (
+        <div className="fixed inset-0 bg-black/40 flex items-center justify-center z-50">
+          <div className="bg-white rounded-lg shadow-xl w-full max-w-lg h-[600px] flex flex-col overflow-hidden">
+            <MessageThread
+              patient={chatPatient}
+              appointmentInfo={chatAppointmentInfo}
+              onBack={() => { setChatPatient(null); setChatAppointmentInfo(undefined); }}
+            />
+          </div>
+        </div>
+      )}
+
       {/* Select Procedures modal — stays on appointments page */}
       {isSelectProceduresOpen && selectProceduresPatientId !== null && (
         <ClaimForm