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/backend/src/db/schema/inventory.ts

@@ -0,0 +1,39 @@
+import { pgTable, uuid, varchar, text, timestamp, boolean, integer } from 'drizzle-orm/pg-core'
+import { companies } from './stores.js'
+
+export const categories = pgTable('category', {
+  id: uuid('id').primaryKey().defaultRandom(),
+  companyId: uuid('company_id')
+    .notNull()
+    .references(() => companies.id),
+  parentId: uuid('parent_id'),
+  name: varchar('name', { length: 255 }).notNull(),
+  description: text('description'),
+  sortOrder: integer('sort_order').notNull().default(0),
+  isActive: boolean('is_active').notNull().default(true),
+  createdAt: timestamp('created_at', { withTimezone: true }).notNull().defaultNow(),
+  updatedAt: timestamp('updated_at', { withTimezone: true }).notNull().defaultNow(),
+})
+
+export const suppliers = pgTable('supplier', {
+  id: uuid('id').primaryKey().defaultRandom(),
+  companyId: uuid('company_id')
+    .notNull()
+    .references(() => companies.id),
+  name: varchar('name', { length: 255 }).notNull(),
+  contactName: varchar('contact_name', { length: 255 }),
+  email: varchar('email', { length: 255 }),
+  phone: varchar('phone', { length: 50 }),
+  website: varchar('website', { length: 255 }),
+  accountNumber: varchar('account_number', { length: 100 }),
+  paymentTerms: varchar('payment_terms', { length: 100 }),
+  notes: text('notes'),
+  isActive: boolean('is_active').notNull().default(true),
+  createdAt: timestamp('created_at', { withTimezone: true }).notNull().defaultNow(),
+  updatedAt: timestamp('updated_at', { withTimezone: true }).notNull().defaultNow(),
+})
+
+export type Category = typeof categories.$inferSelect
+export type CategoryInsert = typeof categories.$inferInsert
+export type Supplier = typeof suppliers.$inferSelect
+export type SupplierInsert = typeof suppliers.$inferInsert