feat: office address, multi-template SMS manager, hardcoded defaults with auto-seed

- Add streetAddress/city/state/zipCode fields to OfficeContact (schema + storage + UI)
- Support {officeAddress} variable in batch reminder SMS
- Replace single SMS template field with full CRUD template list (add/rename/edit/delete)
- Store SMS template list under _sms_template_list; first template synced to batch reminder
- Hardcode all AI chat template defaults into codebase (reminder SMS, greetings, fallback)
- Add seed-templates.ts that auto-seeds default templates for all users on server boot
- Update README: note that templates are auto-configured on first boot

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

apps/Backend/src/storage/seed-templates.ts

@@ -0,0 +1,65 @@
+import { prisma as db } from "@repo/db/client";
+
+// ── Default template values ───────────────────────────────────────────────────
+// Keep these in sync with the frontend constants in ai-chat-settings-card.tsx
+
+export const DEFAULT_REMINDER_SMS =
+  "Hi {firstName}, this is a reminder from {officeName}. You have an appointment on {appointmentDate} at {appointmentTime}. Please come to our office at {officeAddress}. Please reply YES to confirm or NO to reschedule. Thank you!";
+
+export const DEFAULT_AI_CHAT_TEMPLATES = {
+  _ai_chat_reminder_sms:         DEFAULT_REMINDER_SMS,
+  _ai_chat_reminder_greeting:    "Hi! My name is Lisa, the dedicated AI assistant at {officeName}. I can confirm or reschedule your appointment and answer general questions 24/7. I will reply you message at any time you need.",
+  _ai_chat_new_patient_greeting: "Hi! My name is Lisa, the dedicated AI assistant at {officeName}. I can help you schedule an appointment, check your insurance, and answer general questions 24/7. How can I help you today?",
+  _ai_chat_general_fallback:     "Hi! My name is Lisa, the dedicated AI assistant at {officeName}. How can I help you today?",
+  _ai_chat_reschedule_greeting:  "Hi! My name is Lisa, the dedicated AI assistant at {officeName}. I can help you find a new appointment time that works for you. Would you like to reschedule your appointment?",
+};
+
+export const DEFAULT_SMS_TEMPLATE_LIST = JSON.stringify([
+  {
+    id: "default-appt-reminder",
+    name: "Appointment Reminder SMS",
+    body: DEFAULT_REMINDER_SMS,
+  },
+  {
+    id: "default-follow-up",
+    name: "Follow up reminder",
+    body: "Hi {firstName}, this is a follow-up from {officeName}. We wanted to check in with you after your recent appointment. Please don't hesitate to call us if you have any questions.",
+  },
+]);
+
+// ── Auto-seed for a single user ───────────────────────────────────────────────
+// Writes defaults only for keys that are not yet set, so existing data is never
+// overwritten. Safe to call on every boot.
+
+export async function seedTemplatesForUser(userId: number): Promise<void> {
+  const settings = await db.twilioSettings.findUnique({ where: { userId } });
+  const existing = (settings?.templates as Record<string, string>) || {};
+
+  const patch: Record<string, string> = {};
+
+  for (const [key, value] of Object.entries(DEFAULT_AI_CHAT_TEMPLATES)) {
+    if (!existing[key]) patch[key] = value;
+  }
+  if (!existing["_sms_template_list"]) {
+    patch["_sms_template_list"] = DEFAULT_SMS_TEMPLATE_LIST;
+  }
+
+  if (Object.keys(patch).length === 0) return; // nothing to seed
+
+  const updated = { ...existing, ...patch };
+  await db.twilioSettings.upsert({
+    where:  { userId },
+    update: { templates: updated },
+    create: { userId, accountSid: "", authToken: "", phoneNumber: "", templates: updated },
+  });
+}
+
+// ── Seed all existing users ───────────────────────────────────────────────────
+
+export async function seedAllUsersTemplates(): Promise<void> {
+  const users = await db.user.findMany({ select: { id: true } });
+  await Promise.all(users.map((u: { id: number }) => seedTemplatesForUser(u.id)));
+  if (users.length > 0) {
+    console.log(`✅ Seeded AI chat templates for ${users.length} user(s)`);
+  }
+}