Add internal staff IAM: named users, roles, and management permissions.

verae-staff-iam (:3028) is the people directory — owner, billing-admin,
cs, sales, accounting, operator, viewer — with scrypt passwords, sessions,
and an audit log. Admin console login uses it when STAFF_IAM_URL is set
and hides tabs the account cannot use. CS/sales/accounting/staff/fleet
check permissions such as cs.credit and fleet.operate. Shared staff key
remains only as a fallback when IAM is unset.

scripts/gen-module-docs.py

@@ -70,6 +70,7 @@ REPO_READMES = [
     "ui-docs",
     "verae-staff-session",
     "verae-staff-ui",
+    "verae-staff-iam",
 ]
 
 SKIP_PARTS = {"test", "tests", "node_modules", "dist"}