feat: schedule page SMS reminders with AI follow-up and reschedule column

- Add Text Reminder for Column button with per-column checkboxes and AI follow-up toggle (default on)
- Batch reminder endpoint resolves {firstName}, {officeName}, {appointmentDate}, {appointmentTime} from AI chat templates
- Add Reschedule for Column UI (logic TBD)
- Move Download Claim PDF for Column below Reschedule for Column
- Add reminderSms template field to AI Chat Settings with variable hints

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

apps/Frontend/src/components/settings/ai-chat-templates-card.tsx

@@ -12,6 +12,7 @@ type AiChatTemplates = {
   newPatientGreeting: string;
   generalFallback: string;
   rescheduleGreeting: string;
+  reminderSms: string;
 };
 
 type OfficeContact = {
@@ -19,6 +20,8 @@ type OfficeContact = {
 };
 
 const DEFAULTS = {
+  reminderSms:
+    "Hi {firstName}, this is a reminder from {officeName}. You have an appointment on {appointmentDate} at {appointmentTime}. Please reply YES to confirm or NO to reschedule. Thank you!",
   reminderGreeting:
     "Hi! My name is Lisa, the dedicated AI assistant at {officeName}. I can confirm or reschedule your appointment and answer general questions 24/7. How can I help you today?",
   newPatientGreeting:
@@ -36,6 +39,7 @@ function preview(text: string, officeName: string) {
 export function AiChatTemplatesCard() {
   const { toast } = useToast();
 
+  const [reminderSms,        setReminderSms]        = useState(DEFAULTS.reminderSms);
   const [reminderGreeting,   setReminderGreeting]   = useState(DEFAULTS.reminderGreeting);
   const [newPatientGreeting, setNewPatientGreeting] = useState(DEFAULTS.newPatientGreeting);
   const [generalFallback,    setGeneralFallback]    = useState(DEFAULTS.generalFallback);
@@ -67,6 +71,7 @@ export function AiChatTemplatesCard() {
   useEffect(() => {
     if (templates && !initialized.current) {
       initialized.current = true;
+      setReminderSms(templates.reminderSms               || DEFAULTS.reminderSms);
       setReminderGreeting(templates.reminderGreeting     || DEFAULTS.reminderGreeting);
       setNewPatientGreeting(templates.newPatientGreeting || DEFAULTS.newPatientGreeting);
       setGeneralFallback(templates.generalFallback       || DEFAULTS.generalFallback);
@@ -95,6 +100,7 @@ export function AiChatTemplatesCard() {
   const handleSubmit = (e: React.FormEvent) => {
     e.preventDefault();
     saveMutation.mutate({
+      reminderSms:        reminderSms.trim()         || DEFAULTS.reminderSms,
       reminderGreeting:   reminderGreeting.trim()   || DEFAULTS.reminderGreeting,
       newPatientGreeting: newPatientGreeting.trim()  || DEFAULTS.newPatientGreeting,
       generalFallback:    generalFallback.trim()     || DEFAULTS.generalFallback,
@@ -105,6 +111,15 @@ export function AiChatTemplatesCard() {
   const officeName = officeContact?.officeName?.trim() || "";
 
   const templates_list = [
+    {
+      key: "reminderSms" as const,
+      icon: <CalendarCheck className="h-4 w-4 text-primary" />,
+      label: "Reminder SMS Text",
+      description: "Outgoing text sent from the Schedule page. Supports: {firstName}, {officeName}, {appointmentDate}, {appointmentTime}.",
+      value: reminderSms,
+      onChange: setReminderSms,
+      placeholder: DEFAULTS.reminderSms,
+    },
     {
       key: "reminder" as const,
       icon: <CalendarCheck className="h-4 w-4 text-primary" />,
@@ -152,9 +167,12 @@ export function AiChatTemplatesCard() {
           <h3 className="text-lg font-semibold">AI Chat Templates</h3>
         </div>
         <p className="text-sm text-muted-foreground">
-          Customize how your AI assistant introduces itself and responds to patients. Use{" "}
+          Customize the reminder SMS and AI reply templates. Available variables:{" "}
+          <code className="bg-muted px-1 py-0.5 rounded text-xs font-mono">{"{firstName}"}</code>{" "}
           <code className="bg-muted px-1 py-0.5 rounded text-xs font-mono">{"{officeName}"}</code>{" "}
-          as a placeholder — it will be replaced automatically with your dental office name.
+          <code className="bg-muted px-1 py-0.5 rounded text-xs font-mono">{"{appointmentDate}"}</code>{" "}
+          <code className="bg-muted px-1 py-0.5 rounded text-xs font-mono">{"{appointmentTime}"}</code>{" "}
+          — replaced automatically when reminders are sent.
         </p>
 
         {/* Office name hint */}
@@ -208,6 +226,7 @@ export function AiChatTemplatesCard() {
                 variant="ghost"
                 className="text-xs text-muted-foreground"
                 onClick={() => {
+                  setReminderSms(DEFAULTS.reminderSms);
                   setReminderGreeting(DEFAULTS.reminderGreeting);
                   setNewPatientGreeting(DEFAULTS.newPatientGreeting);
                   setGeneralFallback(DEFAULTS.generalFallback);