diff --git a/spec/64_oms_wms_erp_database_schema.sql b/spec/64_oms_wms_erp_database_schema.sql
new file mode 100644
index 00000000..1b84cd16
--- /dev/null
+++ b/spec/64_oms_wms_erp_database_schema.sql
@@ -0,0 +1,471 @@
+-- OMS·WMS·ERP Unified Platform Database Schema v1.0
+-- PostgreSQL 15+
+-- Principles Applied:
+--   3: Data Consistency (SSOT)
+--   5: Normalization (3NF minimum)
+--   6: Denormalization (performance-justified only)
+--  14: Traceability (audit_log on all mutations)
+--  23: Security (NUMERIC for financial precision)
+
+CREATE SCHEMA IF NOT EXISTS quantengine;
+SET search_path = quantengine, public;
+
+-- ===== ENUMS (Type Safety - Principle 19) =====
+
+CREATE TYPE order_status AS ENUM ('DRAFT', 'CONFIRMED', 'SHIPPED', 'DELIVERED', 'CANCELLED');
+CREATE TYPE order_line_status AS ENUM ('PENDING', 'ALLOCATED', 'SHIPPED', 'CANCELLED');
+CREATE TYPE transfer_status AS ENUM ('REQUESTED', 'APPROVED', 'SHIPPED', 'RECEIVED', 'CANCELLED');
+CREATE TYPE product_status AS ENUM ('ACTIVE', 'INACTIVE', 'OBSOLETE');
+CREATE TYPE supplier_status AS ENUM ('ACTIVE', 'INACTIVE', 'SUSPENDED');
+CREATE TYPE customer_status AS ENUM ('ACTIVE', 'INACTIVE', 'SUSPENDED');
+CREATE TYPE gl_account_type AS ENUM ('ASSET', 'LIABILITY', 'EQUITY', 'REVENUE', 'EXPENSE');
+CREATE TYPE voucher_status AS ENUM ('DRAFT', 'POSTED', 'APPROVED', 'VOIDED');
+CREATE TYPE voucher_document_type AS ENUM ('PURCHASE', 'SALES', 'JOURNAL', 'ADJUSTMENT');
+CREATE TYPE inventory_status AS ENUM ('ACTIVE', 'INACTIVE', 'DAMAGED');
+CREATE TYPE unit_of_measure AS ENUM ('EA', 'KG', 'M', 'L', 'BOX');
+CREATE TYPE audit_operation AS ENUM ('CREATE', 'UPDATE', 'DELETE');
+CREATE TYPE user_role AS ENUM ('ADMIN', 'MANAGER', 'OPERATOR', 'VIEWER', 'ANALYST');
+
+-- ===== COMMON/MASTER TABLES =====
+
+CREATE TABLE users (
+  user_id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  email VARCHAR(255) NOT NULL UNIQUE,
+  password_hash VARCHAR(255) NOT NULL,
+  name VARCHAR(255) NOT NULL,
+  role user_role NOT NULL DEFAULT 'VIEWER',
+  status VARCHAR(50) NOT NULL DEFAULT 'ACTIVE',
+  created_by UUID,
+  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  modified_by UUID,
+  modified_at TIMESTAMP,
+  deleted_by UUID,
+  deleted_at TIMESTAMP,
+
+  CONSTRAINT fk_users_created_by FOREIGN KEY (created_by) REFERENCES users(user_id),
+  CONSTRAINT fk_users_modified_by FOREIGN KEY (modified_by) REFERENCES users(user_id),
+  CONSTRAINT fk_users_deleted_by FOREIGN KEY (deleted_by) REFERENCES users(user_id)
+);
+CREATE INDEX idx_users_email ON users(email);
+
+CREATE TABLE warehouses (
+  warehouse_id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  warehouse_code VARCHAR(50) NOT NULL UNIQUE,
+  warehouse_name VARCHAR(255) NOT NULL,
+  location VARCHAR(255),
+  status VARCHAR(50) NOT NULL DEFAULT 'ACTIVE',
+  created_by UUID NOT NULL,
+  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  modified_by UUID,
+  modified_at TIMESTAMP,
+  deleted_by UUID,
+  deleted_at TIMESTAMP,
+
+  CONSTRAINT fk_warehouses_created_by FOREIGN KEY (created_by) REFERENCES users(user_id)
+);
+CREATE INDEX idx_warehouses_code ON warehouses(warehouse_code);
+
+CREATE TABLE product_categories (
+  category_id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  category_name VARCHAR(255) NOT NULL UNIQUE,
+  description TEXT,
+  status VARCHAR(50) NOT NULL DEFAULT 'ACTIVE',
+  created_by UUID NOT NULL,
+  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+  CONSTRAINT fk_categories_created_by FOREIGN KEY (created_by) REFERENCES users(user_id)
+);
+
+-- ===== OMS: ORDER MANAGEMENT =====
+
+CREATE TABLE customers (
+  customer_id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  customer_code VARCHAR(50) NOT NULL UNIQUE,
+  customer_name VARCHAR(255) NOT NULL,
+  email VARCHAR(255),
+  phone VARCHAR(20),
+  business_registration VARCHAR(50),
+  status customer_status NOT NULL DEFAULT 'ACTIVE',
+  created_by UUID NOT NULL,
+  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  modified_by UUID,
+  modified_at TIMESTAMP,
+  deleted_by UUID,
+  deleted_at TIMESTAMP,
+
+  CONSTRAINT fk_customers_created_by FOREIGN KEY (created_by) REFERENCES users(user_id)
+);
+CREATE INDEX idx_customers_code ON customers(customer_code);
+CREATE INDEX idx_customers_email ON customers(email);
+
+CREATE TABLE orders (
+  order_id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  order_no VARCHAR(50) NOT NULL UNIQUE,
+  customer_id UUID NOT NULL,
+  order_date DATE NOT NULL DEFAULT CURRENT_DATE,
+  total_amount NUMERIC(19,4) NOT NULL DEFAULT 0.0,
+  status order_status NOT NULL DEFAULT 'DRAFT',
+  created_by UUID NOT NULL,
+  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  modified_by UUID,
+  modified_at TIMESTAMP,
+  deleted_by UUID,
+  deleted_at TIMESTAMP,
+
+  CONSTRAINT fk_orders_customer FOREIGN KEY (customer_id) REFERENCES customers(customer_id),
+  CONSTRAINT fk_orders_created_by FOREIGN KEY (created_by) REFERENCES users(user_id),
+  CONSTRAINT chk_total_amount CHECK (total_amount >= 0)
+);
+CREATE INDEX idx_orders_no ON orders(order_no);
+CREATE INDEX idx_orders_customer_id ON orders(customer_id);
+CREATE INDEX idx_orders_status ON orders(status);
+CREATE INDEX idx_orders_order_date ON orders(order_date);
+
+CREATE TABLE order_lines (
+  line_id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  order_id UUID NOT NULL,
+  line_no SMALLINT NOT NULL,
+  product_id UUID NOT NULL,
+  quantity NUMERIC(19,4) NOT NULL,
+  quantity_unit unit_of_measure NOT NULL,
+  unit_price NUMERIC(19,4) NOT NULL,
+  line_total NUMERIC(19,4) NOT NULL,
+  status order_line_status NOT NULL DEFAULT 'PENDING',
+  created_by UUID NOT NULL,
+  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  modified_by UUID,
+  modified_at TIMESTAMP,
+  deleted_by UUID,
+  deleted_at TIMESTAMP,
+
+  CONSTRAINT fk_order_lines_order FOREIGN KEY (order_id) REFERENCES orders(order_id),
+  CONSTRAINT fk_order_lines_product FOREIGN KEY (product_id) REFERENCES products(product_id),
+  CONSTRAINT fk_order_lines_created_by FOREIGN KEY (created_by) REFERENCES users(user_id),
+  CONSTRAINT uk_order_lines_order_lineno UNIQUE (order_id, line_no),
+  CONSTRAINT chk_quantity CHECK (quantity > 0),
+  CONSTRAINT chk_unit_price CHECK (unit_price >= 0),
+  CONSTRAINT chk_line_total CHECK (line_total >= 0)
+);
+CREATE INDEX idx_order_lines_order_id ON order_lines(order_id);
+CREATE INDEX idx_order_lines_product_id ON order_lines(product_id);
+
+-- ===== WMS: WAREHOUSE MANAGEMENT =====
+
+CREATE TABLE inventory (
+  inventory_id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  warehouse_id UUID NOT NULL,
+  product_id UUID NOT NULL,
+  qty_on_hand NUMERIC(19,4) NOT NULL DEFAULT 0.0,
+  qty_reserved NUMERIC(19,4) NOT NULL DEFAULT 0.0,
+  qty_available NUMERIC(19,4) NOT NULL GENERATED ALWAYS AS (qty_on_hand - qty_reserved) STORED,
+  last_adjustment_date TIMESTAMP,
+  status inventory_status NOT NULL DEFAULT 'ACTIVE',
+  created_by UUID NOT NULL,
+  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  modified_by UUID,
+  modified_at TIMESTAMP,
+  deleted_by UUID,
+  deleted_at TIMESTAMP,
+
+  CONSTRAINT fk_inventory_warehouse FOREIGN KEY (warehouse_id) REFERENCES warehouses(warehouse_id),
+  CONSTRAINT fk_inventory_product FOREIGN KEY (product_id) REFERENCES products(product_id),
+  CONSTRAINT fk_inventory_created_by FOREIGN KEY (created_by) REFERENCES users(user_id),
+  CONSTRAINT uk_inventory_warehouse_product UNIQUE (warehouse_id, product_id),
+  CONSTRAINT chk_qty_on_hand CHECK (qty_on_hand >= 0),
+  CONSTRAINT chk_qty_reserved CHECK (qty_reserved >= 0)
+);
+CREATE INDEX idx_inventory_warehouse_id ON inventory(warehouse_id);
+CREATE INDEX idx_inventory_product_id ON inventory(product_id);
+
+CREATE TABLE stock_transfers (
+  transfer_id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  transfer_no VARCHAR(50) NOT NULL UNIQUE,
+  from_warehouse_id UUID NOT NULL,
+  to_warehouse_id UUID NOT NULL,
+  product_id UUID NOT NULL,
+  quantity NUMERIC(19,4) NOT NULL,
+  reason TEXT,
+  status transfer_status NOT NULL DEFAULT 'REQUESTED',
+  created_by UUID NOT NULL,
+  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  modified_by UUID,
+  modified_at TIMESTAMP,
+  deleted_by UUID,
+  deleted_at TIMESTAMP,
+
+  CONSTRAINT fk_transfers_from_warehouse FOREIGN KEY (from_warehouse_id) REFERENCES warehouses(warehouse_id),
+  CONSTRAINT fk_transfers_to_warehouse FOREIGN KEY (to_warehouse_id) REFERENCES warehouses(warehouse_id),
+  CONSTRAINT fk_transfers_product FOREIGN KEY (product_id) REFERENCES products(product_id),
+  CONSTRAINT fk_transfers_created_by FOREIGN KEY (created_by) REFERENCES users(user_id),
+  CONSTRAINT chk_quantity CHECK (quantity > 0),
+  CONSTRAINT chk_different_warehouses CHECK (from_warehouse_id != to_warehouse_id)
+);
+CREATE INDEX idx_stock_transfers_no ON stock_transfers(transfer_no);
+CREATE INDEX idx_stock_transfers_from_warehouse ON stock_transfers(from_warehouse_id);
+CREATE INDEX idx_stock_transfers_to_warehouse ON stock_transfers(to_warehouse_id);
+CREATE INDEX idx_stock_transfers_status ON stock_transfers(status);
+
+-- ===== ERP: ENTERPRISE RESOURCE PLANNING =====
+
+CREATE TABLE products (
+  product_id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  sku VARCHAR(50) NOT NULL UNIQUE,
+  product_name VARCHAR(255) NOT NULL,
+  category_id UUID,
+  unit_of_measure unit_of_measure NOT NULL DEFAULT 'EA',
+  status product_status NOT NULL DEFAULT 'ACTIVE',
+  created_by UUID NOT NULL,
+  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  modified_by UUID,
+  modified_at TIMESTAMP,
+  deleted_by UUID,
+  deleted_at TIMESTAMP,
+
+  CONSTRAINT fk_products_category FOREIGN KEY (category_id) REFERENCES product_categories(category_id),
+  CONSTRAINT fk_products_created_by FOREIGN KEY (created_by) REFERENCES users(user_id)
+);
+CREATE INDEX idx_products_sku ON products(sku);
+CREATE INDEX idx_products_status ON products(status);
+
+CREATE TABLE suppliers (
+  supplier_id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  supplier_code VARCHAR(50) NOT NULL UNIQUE,
+  supplier_name VARCHAR(255) NOT NULL,
+  email VARCHAR(255),
+  phone VARCHAR(20),
+  business_registration VARCHAR(50),
+  status supplier_status NOT NULL DEFAULT 'ACTIVE',
+  created_by UUID NOT NULL,
+  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  modified_by UUID,
+  modified_at TIMESTAMP,
+  deleted_by UUID,
+  deleted_at TIMESTAMP,
+
+  CONSTRAINT fk_suppliers_created_by FOREIGN KEY (created_by) REFERENCES users(user_id)
+);
+CREATE INDEX idx_suppliers_code ON suppliers(supplier_code);
+
+CREATE TABLE gl_accounts (
+  account_id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  account_code VARCHAR(50) NOT NULL UNIQUE,
+  account_name VARCHAR(255) NOT NULL,
+  account_type gl_account_type NOT NULL,
+  status VARCHAR(50) NOT NULL DEFAULT 'ACTIVE',
+  created_by UUID NOT NULL,
+  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  modified_by UUID,
+  modified_at TIMESTAMP,
+  deleted_by UUID,
+  deleted_at TIMESTAMP,
+
+  CONSTRAINT fk_gl_accounts_created_by FOREIGN KEY (created_by) REFERENCES users(user_id)
+);
+CREATE INDEX idx_gl_accounts_code ON gl_accounts(account_code);
+CREATE INDEX idx_gl_accounts_type ON gl_accounts(account_type);
+
+CREATE TABLE vouchers (
+  voucher_id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  voucher_no VARCHAR(50) NOT NULL UNIQUE,
+  document_date DATE NOT NULL,
+  document_type voucher_document_type NOT NULL,
+  description TEXT,
+  total_debit NUMERIC(19,4) NOT NULL DEFAULT 0.0,
+  total_credit NUMERIC(19,4) NOT NULL DEFAULT 0.0,
+  status voucher_status NOT NULL DEFAULT 'DRAFT',
+  created_by UUID NOT NULL,
+  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  modified_by UUID,
+  modified_at TIMESTAMP,
+  deleted_by UUID,
+  deleted_at TIMESTAMP,
+
+  CONSTRAINT fk_vouchers_created_by FOREIGN KEY (created_by) REFERENCES users(user_id),
+  CONSTRAINT chk_totals_balance CHECK (total_debit = total_credit)
+);
+CREATE INDEX idx_vouchers_no ON vouchers(voucher_no);
+CREATE INDEX idx_vouchers_document_date ON vouchers(document_date);
+CREATE INDEX idx_vouchers_status ON vouchers(status);
+
+CREATE TABLE voucher_lines (
+  voucher_line_id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  voucher_id UUID NOT NULL,
+  line_no SMALLINT NOT NULL,
+  account_id UUID NOT NULL,
+  debit_amount NUMERIC(19,4) NOT NULL DEFAULT 0.0,
+  credit_amount NUMERIC(19,4) NOT NULL DEFAULT 0.0,
+  description TEXT,
+  created_by UUID NOT NULL,
+  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+  CONSTRAINT fk_voucher_lines_voucher FOREIGN KEY (voucher_id) REFERENCES vouchers(voucher_id),
+  CONSTRAINT fk_voucher_lines_account FOREIGN KEY (account_id) REFERENCES gl_accounts(account_id),
+  CONSTRAINT fk_voucher_lines_created_by FOREIGN KEY (created_by) REFERENCES users(user_id),
+  CONSTRAINT uk_voucher_lines_voucher_lineno UNIQUE (voucher_id, line_no),
+  CONSTRAINT chk_debit_amount CHECK (debit_amount >= 0),
+  CONSTRAINT chk_credit_amount CHECK (credit_amount >= 0),
+  CONSTRAINT chk_either_debit_or_credit CHECK ((debit_amount > 0 OR credit_amount > 0) AND NOT (debit_amount > 0 AND credit_amount > 0))
+);
+CREATE INDEX idx_voucher_lines_voucher_id ON voucher_lines(voucher_id);
+CREATE INDEX idx_voucher_lines_account_id ON voucher_lines(account_id);
+
+-- ===== AUDIT TRAIL (Principle 14: Traceability) =====
+
+CREATE TABLE audit_logs (
+  audit_id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  entity_type VARCHAR(50) NOT NULL,
+  entity_id UUID NOT NULL,
+  operation audit_operation NOT NULL,
+  old_value JSONB,
+  new_value JSONB,
+  changed_by UUID NOT NULL,
+  changed_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  reason TEXT,
+
+  CONSTRAINT fk_audit_logs_changed_by FOREIGN KEY (changed_by) REFERENCES users(user_id)
+);
+CREATE INDEX idx_audit_logs_entity ON audit_logs(entity_type, entity_id);
+CREATE INDEX idx_audit_logs_changed_at ON audit_logs(changed_at);
+CREATE INDEX idx_audit_logs_operation ON audit_logs(operation);
+
+-- ===== AUDIT TRIGGER (Principle 14: Automatic Traceability) =====
+
+CREATE OR REPLACE FUNCTION audit_trigger()
+RETURNS TRIGGER AS $$
+DECLARE
+  v_entity_type VARCHAR;
+  v_operation audit_operation;
+BEGIN
+  v_entity_type := TG_TABLE_NAME;
+
+  IF TG_OP = 'INSERT' THEN
+    v_operation := 'CREATE'::audit_operation;
+    INSERT INTO audit_logs (entity_type, entity_id, operation, new_value, changed_by, changed_at)
+    VALUES (v_entity_type, NEW.id, v_operation, to_jsonb(NEW), NEW.created_by, CURRENT_TIMESTAMP);
+    RETURN NEW;
+
+  ELSIF TG_OP = 'UPDATE' THEN
+    v_operation := 'UPDATE'::audit_operation;
+    INSERT INTO audit_logs (entity_type, entity_id, operation, old_value, new_value, changed_by, changed_at)
+    VALUES (v_entity_type, OLD.id, v_operation, to_jsonb(OLD), to_jsonb(NEW), NEW.modified_by, CURRENT_TIMESTAMP);
+    RETURN NEW;
+
+  ELSIF TG_OP = 'DELETE' THEN
+    v_operation := 'DELETE'::audit_operation;
+    INSERT INTO audit_logs (entity_type, entity_id, operation, old_value, changed_by, changed_at)
+    VALUES (v_entity_type, OLD.id, v_operation, to_jsonb(OLD), OLD.deleted_by, CURRENT_TIMESTAMP);
+    RETURN OLD;
+  END IF;
+
+  RETURN NULL;
+END;
+$$ LANGUAGE plpgsql;
+
+-- Note: Trigger creation for individual tables omitted to keep schema focused.
+-- In production: CREATE TRIGGER for orders, inventory, products, etc.
+
+-- ===== VIEWS (Convenience, Principle 3: Data Consistency) =====
+
+CREATE VIEW v_order_summary AS
+SELECT
+  o.order_id,
+  o.order_no,
+  c.customer_name,
+  o.order_date,
+  COUNT(ol.line_id) as line_count,
+  SUM(ol.line_total) as calculated_total,
+  o.total_amount,
+  o.status,
+  o.created_at
+FROM orders o
+LEFT JOIN customers c ON o.customer_id = c.customer_id
+LEFT JOIN order_lines ol ON o.order_id = ol.order_id
+WHERE o.deleted_at IS NULL
+GROUP BY o.order_id, o.order_no, c.customer_name, o.order_date, o.total_amount, o.status, o.created_at;
+
+CREATE VIEW v_inventory_summary AS
+SELECT
+  i.warehouse_id,
+  w.warehouse_name,
+  i.product_id,
+  p.sku,
+  p.product_name,
+  i.qty_on_hand,
+  i.qty_reserved,
+  i.qty_available,
+  i.status,
+  i.modified_at
+FROM inventory i
+LEFT JOIN warehouses w ON i.warehouse_id = w.warehouse_id
+LEFT JOIN products p ON i.product_id = p.product_id
+WHERE i.deleted_at IS NULL;
+
+CREATE VIEW v_voucher_totals AS
+SELECT
+  v.voucher_id,
+  v.voucher_no,
+  v.document_type,
+  v.document_date,
+  SUM(COALESCE(vl.debit_amount, 0)) as calculated_debit,
+  SUM(COALESCE(vl.credit_amount, 0)) as calculated_credit,
+  v.total_debit,
+  v.total_credit,
+  v.status,
+  COUNT(vl.voucher_line_id) as line_count
+FROM vouchers v
+LEFT JOIN voucher_lines vl ON v.voucher_id = vl.voucher_id
+WHERE v.deleted_at IS NULL
+GROUP BY v.voucher_id, v.voucher_no, v.document_type, v.document_date, v.total_debit, v.total_credit, v.status;
+
+-- ===== INITIAL DATA (Seed) =====
+
+-- Create initial admin user
+INSERT INTO users (user_id, email, password_hash, name, role, status, created_by, created_at)
+VALUES (
+  '00000000-0000-0000-0000-000000000001'::UUID,
+  'admin@quantengine.dev',
+  '$2b$12$R9h7cIPz0gi.URNNX3kh2OPST9/PgBkqquzi.Ss7KIUgO2t0jWMUe', -- bcrypt: admin123!
+  'System Administrator',
+  'ADMIN',
+  'ACTIVE',
+  '00000000-0000-0000-0000-000000000001'::UUID,
+  CURRENT_TIMESTAMP
+) ON CONFLICT DO NOTHING;
+
+-- Create initial warehouses
+INSERT INTO warehouses (warehouse_code, warehouse_name, location, status, created_by, created_at)
+VALUES
+  ('WH-SEOUL', 'Seoul Main Warehouse', 'Seoul, KR', 'ACTIVE', '00000000-0000-0000-0000-000000000001'::UUID, CURRENT_TIMESTAMP),
+  ('WH-BUSAN', 'Busan Distribution Center', 'Busan, KR', 'ACTIVE', '00000000-0000-0000-0000-000000000001'::UUID, CURRENT_TIMESTAMP),
+  ('WH-INCHEON', 'Incheon Port Warehouse', 'Incheon, KR', 'ACTIVE', '00000000-0000-0000-0000-000000000001'::UUID, CURRENT_TIMESTAMP)
+ON CONFLICT DO NOTHING;
+
+-- Create initial product category
+INSERT INTO product_categories (category_name, description, status, created_by, created_at)
+VALUES
+  ('Standard Products', 'Regular inventory items', 'ACTIVE', '00000000-0000-0000-0000-000000000001'::UUID, CURRENT_TIMESTAMP),
+  ('Premium Products', 'High-value items', 'ACTIVE', '00000000-0000-0000-0000-000000000001'::UUID, CURRENT_TIMESTAMP)
+ON CONFLICT DO NOTHING;
+
+-- ===== GRANTS (Security - Principle 23) =====
+
+-- Application role (read-write for normal operations)
+CREATE ROLE quantengine_app LOGIN PASSWORD 'CHANGE_ME_PROD';
+GRANT USAGE ON SCHEMA quantengine TO quantengine_app;
+GRANT SELECT, INSERT, UPDATE ON ALL TABLES IN SCHEMA quantengine TO quantengine_app;
+GRANT USAGE, SELECT ON ALL SEQUENCES IN SCHEMA quantengine TO quantengine_app;
+GRANT EXECUTE ON ALL FUNCTIONS IN SCHEMA quantengine TO quantengine_app;
+
+-- Read-only role (for analytics/reporting)
+CREATE ROLE quantengine_readonly LOGIN PASSWORD 'CHANGE_ME_PROD';
+GRANT USAGE ON SCHEMA quantengine TO quantengine_readonly;
+GRANT SELECT ON ALL TABLES IN SCHEMA quantengine TO quantengine_readonly;
+GRANT SELECT ON ALL VIEWS IN SCHEMA quantengine TO quantengine_readonly;
+
+-- ===== COMMENTS (Documentation - Principle 28) =====
+
+COMMENT ON SCHEMA quantengine IS 'OMS·WMS·ERP Unified Platform - Phase 0 Database Schema';
+COMMENT ON TABLE orders IS 'Order master records (OMS) - Principle 14: Complete audit trail via audit_logs';
+COMMENT ON TABLE inventory IS 'Warehouse inventory positions (WMS) - qty_available computed from on_hand - reserved';
+COMMENT ON TABLE audit_logs IS 'Universal change audit trail - every mutation logged for compliance + recovery (Principle 14)';
+COMMENT ON TABLE vouchers IS 'Accounting journal entries (ERP) - Principle 23: NUMERIC(19,4) for decimal precision';