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/results/ShoppingVendorGroupByResult.schema.ts

@@ -0,0 +1,42 @@
+import * as z from 'zod';
+export const ShoppingVendorGroupByResultSchema = z.array(z.object({
+  id: z.number().int(),
+  userId: z.number().int(),
+  vendorName: z.string(),
+  websiteUrl: z.string(),
+  loginUsername: z.string(),
+  loginPassword: z.string(),
+  _count: z.object({
+    id: z.number(),
+    userId: z.number(),
+    vendorName: z.number(),
+    websiteUrl: z.number(),
+    loginUsername: z.number(),
+    loginPassword: z.number(),
+    user: z.number()
+  }).optional(),
+  _sum: z.object({
+    id: z.number().nullable(),
+    userId: z.number().nullable()
+  }).nullable().optional(),
+  _avg: z.object({
+    id: z.number().nullable(),
+    userId: z.number().nullable()
+  }).nullable().optional(),
+  _min: z.object({
+    id: z.number().int().nullable(),
+    userId: z.number().int().nullable(),
+    vendorName: z.string().nullable(),
+    websiteUrl: z.string().nullable(),
+    loginUsername: z.string().nullable(),
+    loginPassword: z.string().nullable()
+  }).nullable().optional(),
+  _max: z.object({
+    id: z.number().int().nullable(),
+    userId: z.number().int().nullable(),
+    vendorName: z.string().nullable(),
+    websiteUrl: z.string().nullable(),
+    loginUsername: z.string().nullable(),
+    loginPassword: z.string().nullable()
+  }).nullable().optional()
+}));