feat: manufacturers route — list, get, create

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

src/shared/schemas.ts

@@ -146,6 +146,18 @@ export const bulkUpsertGlobalItemsSchema = z.object({
 	items: z.array(upsertGlobalItemSchema).min(1).max(100),
 });
 
+export const createManufacturerSchema = z.object({
+	name: z.string().min(1).max(200),
+	slug: z
+		.string()
+		.min(1)
+		.max(100)
+		.regex(/^[a-z0-9-]+$/, "Slug must be lowercase alphanumeric with hyphens"),
+	website: z.string().url(),
+	tier: z.number().int().min(1).max(3).optional(),
+	country: z.string().length(2).optional(),
+});
+
 // Profile schemas
 export const updateProfileSchema = z.object({
 	displayName: z.string().max(100).optional(),