fix(ct): teardown litter users/calendars after API suites

Track users/calendars created via register_and_login and create_calendar;
soft-delete via admin API in end_per_suite. Skip with CT_KEEP_DATA=1.
Safety-net soft-deletes remaining @test.local users.

Fixes EventHub/EventHubBack#65

scripts/run-stand-api-tests.sh

@@ -2,6 +2,11 @@
 # Full API CT suite against live stand (remote) + smoke-core on stand host.
 # Usage: run-stand-api-tests.sh <ift|stage>
 # Requires: ADMIN_* from load-stand-api-env.sh; SSH_* for smoke-core on stand.
+#
+# Litter cleanup: after each CT suite, api_test_runner:cleanup_tracked/0
+# soft-deletes tracked calendars/users via admin API (and @test.local safety-net).
+# Skip teardown: CT_KEEP_DATA=1 (data remains on the stand).
+# Soft-delete ≠ hard wipe; full clean slate = ops Mnesia volume wipe.
 set -euo pipefail
 
 STAND="${1:?stand: ift|stage}"
@@ -134,6 +139,7 @@ docker run --rm --network=host \
   -e "ADMIN_MODER_PASSWORD=${ADMIN_MODER_PASSWORD:-}" \
   -e "ADMIN_SUPPORT_EMAIL=${ADMIN_SUPPORT_EMAIL:-}" \
   -e "ADMIN_SUPPORT_PASSWORD=${ADMIN_SUPPORT_PASSWORD:-}" \
+  -e "CT_KEEP_DATA=${CT_KEEP_DATA:-}" \
   "${IMAGE}"
 CT_RC=$?
 set -e