feat: add AI Dental Shopping section with sidebar nav and Login Info page

- Add AI Dental Shopping to sidebar with Search/Tag and Login Info sub-pages
- Build full-stack Login Info CRUD: save vendor name, website, username, password per user
- Add ShoppingVendor Prisma model, run db push, regenerate client and Zod schemas
- Add storage layer, REST API at /api/shopping-vendors/, and frontend table with add/edit/delete modal

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

apps/Backend/src/storage/index.ts

@@ -24,6 +24,7 @@ import { officeContactStorage } from "./office-contact-storage";
 import { procedureTimeslotStorage } from "./procedure-timeslot-storage";
 import { insuranceContactStorage } from "./insurance-contact-storage";
 import { commissionsStorage } from "./commissions-storage";
+import { shoppingVendorStorage } from "./shopping-vendor-storage";
 
 
 export const storage = {
@@ -51,6 +52,7 @@ export const storage = {
   ...procedureTimeslotStorage,
   ...insuranceContactStorage,
   ...commissionsStorage,
+  ...shoppingVendorStorage,
 
 };