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/Backend/src/routes/ai-settings.ts

@@ -53,8 +53,8 @@ router.put("/chat-templates", async (req: Request, res: Response): Promise<any>
   try {
     const userId = req.user?.id;
     if (!userId) return res.status(401).json({ message: "Unauthorized" });
-    const { reminderGreeting, newPatientGreeting, generalFallback, rescheduleGreeting } = req.body;
-    await storage.saveAiChatTemplates(userId, { reminderGreeting, newPatientGreeting, generalFallback, rescheduleGreeting });
+    const { reminderGreeting, newPatientGreeting, generalFallback, rescheduleGreeting, reminderSms } = req.body;
+    await storage.saveAiChatTemplates(userId, { reminderGreeting, newPatientGreeting, generalFallback, rescheduleGreeting, reminderSms });
     const updated = await storage.getAiChatTemplates(userId);
     return res.status(200).json(updated);
   } catch (err) {