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>

packages/db/shared/schemas/variants/input/index.ts

@@ -14,6 +14,7 @@ export { ClaimInputSchema } from './Claim.input';
 export { ServiceLineInputSchema } from './ServiceLine.input';
 export { ClaimFileInputSchema } from './ClaimFile.input';
 export { InsuranceCredentialInputSchema } from './InsuranceCredential.input';
+export { ShoppingVendorInputSchema } from './ShoppingVendor.input';
 export { PdfGroupInputSchema } from './PdfGroup.input';
 export { PdfFileInputSchema } from './PdfFile.input';
 export { PaymentInputSchema } from './Payment.input';