Add categories and suppliers with CRUD routes

- category table with hierarchical parent_id, sort ordering, soft-delete
- supplier table with contact info, account number, payment terms
- CRUD routes for both with search on suppliers
- Zod validation schemas in @forte/shared
- Products will link to suppliers via join table (many-to-many)
- 26 tests passing

packages/shared/src/schemas/index.ts

@@ -15,3 +15,16 @@ export type {
   MemberCreateInput,
   MemberUpdateInput,
 } from './account.schema.js'
+
+export {
+  CategoryCreateSchema,
+  CategoryUpdateSchema,
+  SupplierCreateSchema,
+  SupplierUpdateSchema,
+} from './inventory.schema.js'
+export type {
+  CategoryCreateInput,
+  CategoryUpdateInput,
+  SupplierCreateInput,
+  SupplierUpdateInput,
+} from './inventory.schema.js'