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/index.ts

@@ -4,6 +4,7 @@ import http from "http";
 import { initSocket } from "./socket";
 import { startSeleniumWorker } from "./queue/workers/seleniumWorker";
 import { startOcrWorker } from "./queue/workers/ocrWorker";
+import { seedAllUsersTemplates } from "./storage/seed-templates";
 
 dotenv.config();
 
@@ -29,6 +30,9 @@ server.listen(PORT, HOST, () => {
   console.log(
     `✅ Server running in ${NODE_ENV} mode at http://${HOST}:${PORT}`
   );
+  seedAllUsersTemplates().catch((err) =>
+    console.error("⚠️  Template seed failed:", err)
+  );
 });
 
 // Handle startup errors