chore(release): public-release readiness fixes for 1.1.18

- CHANGELOG.md now embeds full app-level release notes for submodule bumps.
- .env.example uses explicit CHANGE-ME placeholders instead of realistic-looking defaults.
- config.example comments describe the actual CONF_SECRETS mechanism.
- setup.sh summary no longer prints generated passwords to stdout.
- bootstrap.js fails hard instead of falling back to weak default passwords.

Note: submodule pins will be updated to v1.1.16 after the app PRs merge.

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

setup.sh

@@ -717,13 +717,13 @@ echo "                      first-run fallback: http://127.0.0.1:${SSO_PORT:-300
 echo "  Proxy mgmt UI:      https://${PROXY_HOST}"
 echo "                      first-run fallback: http://127.0.0.1:${MGMT_PORT:-3000}"
 echo
-echo "  First admin login:"
+echo "  First admin login credentials are in ./config/sso-secrets.js:"
 echo "    user: ${ADMIN_UID}"
-echo "    pass: ${ADMIN_PASS}"
+echo "    pass: bootstrap.adminPass"
 echo
 echo "  Proxy local admin (anti-lockout fallback if the SSO is unreachable):"
 echo "    user: proxyadmin2"
-echo "    pass: ${PROXY_LOCAL_ADMIN_PASS}"
+echo "    pass: auth.localAdminPass in ./config/proxy-secrets.js"
 echo "    (only shown when the account is first created; edit ./config/proxy-secrets.js"
 echo "    or use the proxy UI to change it afterward)"
 echo