-- v1.2: Add subdomain column to tenants table (nexus_master)
-- This migration runs against the MASTER database, not tenant databases.

ALTER TABLE tenants ADD COLUMN IF NOT EXISTS subdomain VARCHAR(100) UNIQUE;
CREATE INDEX IF NOT EXISTS idx_tenants_subdomain ON tenants(subdomain);

COMMENT ON COLUMN tenants.subdomain IS 'URL subdomain for tenant POS access, e.g. refac-lopez -> refac-lopez.nexusautoparts.com';