feat: backend MVP (auth/rbac, catalog, orders, fulfillment, invoices) + specs + scaffolds

apps/api/migrations/0002_identity.sql

@@ -0,0 +1,28 @@
+CREATE TYPE user_role AS ENUM ('platform_admin', 'shop_owner', 'shop_staff', 'customer');
+
+CREATE TYPE shop_status AS ENUM ('active', 'suspended');
+
+CREATE TABLE shops (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    name JSONB NOT NULL,
+    slug TEXT NOT NULL UNIQUE,
+    status shop_status NOT NULL DEFAULT 'active',
+    created_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE TABLE users (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    email TEXT NOT NULL UNIQUE,
+    password_hash TEXT NOT NULL,
+    display_name TEXT NOT NULL,
+    role user_role NOT NULL DEFAULT 'customer',
+    shop_id UUID REFERENCES shops (id),
+    locale TEXT NOT NULL DEFAULT 'en',
+    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+    CONSTRAINT shop_role_requires_shop CHECK (
+        role IN ('customer', 'platform_admin')
+        OR shop_id IS NOT NULL
+    )
+);
+
+CREATE INDEX idx_users_shop ON users (shop_id);