[EPIC-002] feat: Add user_id FK to employees + rename warehouse_type

T2.1: Renamed warehouse_type -> construction_warehouse_type
      in almacenes_proyecto to avoid naming conflict with ERP-Core

T2.3: Added user_id column to hr.employees
      - Optional FK to auth.users (employee may not have system access)
      - Unique constraint for 1:1 mapping
      - Conditional FK (only created if auth.users exists)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

schemas/02-hr-schema-ddl.sql

@@ -59,9 +59,12 @@ CREATE TABLE IF NOT EXISTS hr.employees (
     created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
     updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
     created_by UUID REFERENCES auth.users(id),
+    -- Mapeo a usuario del sistema (opcional - empleado puede no tener acceso)
+    user_id UUID,
 
     CONSTRAINT uq_employees_codigo UNIQUE (tenant_id, codigo),
-    CONSTRAINT uq_employees_curp UNIQUE (tenant_id, curp)
+    CONSTRAINT uq_employees_curp UNIQUE (tenant_id, curp),
+    CONSTRAINT uq_employees_user_id UNIQUE (user_id)
 );
 
 -- Tabla: Puestos
@@ -85,6 +88,20 @@ ALTER TABLE hr.employees
     ADD CONSTRAINT fk_employees_puesto
     FOREIGN KEY (puesto_id) REFERENCES hr.puestos(id);
 
+-- FK condicional: employees.user_id → auth.users (si tabla existe)
+DO $$
+BEGIN
+    IF EXISTS (SELECT 1 FROM pg_tables WHERE schemaname = 'auth' AND tablename = 'users') THEN
+        IF NOT EXISTS (SELECT 1 FROM pg_constraint WHERE conname = 'fk_employees_user') THEN
+            ALTER TABLE hr.employees
+            ADD CONSTRAINT fk_employees_user
+            FOREIGN KEY (user_id) REFERENCES auth.users(id)
+            ON DELETE SET NULL;
+            RAISE NOTICE 'FK creada: hr.employees.user_id → auth.users';
+        END IF;
+    END IF;
+END $$;
+
 -- Tabla: Asignacion de empleados a obras
 CREATE TABLE IF NOT EXISTS hr.employee_fraccionamientos (
     id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
@@ -107,6 +124,7 @@ CREATE TABLE IF NOT EXISTS hr.employee_fraccionamientos (
 CREATE INDEX IF NOT EXISTS idx_employees_tenant ON hr.employees(tenant_id);
 CREATE INDEX IF NOT EXISTS idx_employees_estado ON hr.employees(estado);
 CREATE INDEX IF NOT EXISTS idx_employees_puesto ON hr.employees(puesto_id);
+CREATE INDEX IF NOT EXISTS idx_employees_user_id ON hr.employees(user_id);
 CREATE INDEX IF NOT EXISTS idx_puestos_tenant ON hr.puestos(tenant_id);
 CREATE INDEX IF NOT EXISTS idx_employee_fraccionamientos_employee ON hr.employee_fraccionamientos(employee_id);
 CREATE INDEX IF NOT EXISTS idx_employee_fraccionamientos_fraccionamiento ON hr.employee_fraccionamientos(fraccionamiento_id);

schemas/06-inventory-ext-schema-ddl.sql

@@ -55,7 +55,7 @@ CREATE TABLE IF NOT EXISTS inventory.almacenes_proyecto (
     tenant_id UUID NOT NULL REFERENCES auth.tenants(id) ON DELETE CASCADE,
     warehouse_id UUID NOT NULL,  -- FK a inventory.warehouses (ERP Core)
     fraccionamiento_id UUID NOT NULL REFERENCES construction.fraccionamientos(id),
-    warehouse_type inventory.warehouse_type_construction NOT NULL DEFAULT 'obra',
+    construction_warehouse_type inventory.warehouse_type_construction NOT NULL DEFAULT 'obra',
     location_description TEXT,
     location GEOMETRY(POINT, 4326),
     responsible_id UUID REFERENCES auth.users(id),