docs(uat): add TC-API-3.30 schema-safe reset verification (GRO-2722)

UAT_PLAYBOOK.md §3 — new test case TC-API-3.30:
trigger reset-demo-data CronJob manually, confirm job succeeds,
public tables/enums and drizzle schema survive, demo data reseeded,
/api/readyz stays 200.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

UAT_PLAYBOOK.md

@@ -196,6 +196,7 @@ Geocoding turns a client's street address into `latitude`/`longitude` + `geocode
 | TC-API-3.27 | Verify coat_type enum has all seed values | After UAT seed completes, inspect the coat_type enum on the UAT DB — it must contain: short, medium, long, double, wire, silky, curly, hairless | UAT seed jobs (`reset-demo-data`, `seed-test-data`) complete 1/1 with no `enum_in` error; coat_type includes all 8 values used by seed.ts `coatTypePool` |
 | TC-API-3.28 | Verify pet_size_category enum has all seed values | After UAT seed completes, inspect the pet_size_category enum on the UAT DB — it must contain: small, medium, large, extra_large | UAT seed jobs (`reset-demo-data`, `seed-test-data`) complete 1/1 with no `enum_in` error; pet_size_category includes all 4 values used by seed.ts `petSizeCategoryPool` (regression for GRO-1999, mirrors TC-API-3.27) |
 | TC-API-3.29 | Verify `reset-demo-data` CronJob does not fail with FK 23503 on `invoice_tip_splits` (GRO-2123) | Trigger the CronJob manually: `kubectl create job --from=cronjob/reset-demo-data verify-gro2123 -n groombook-uat`. Wait for pod to terminate. Inspect logs: `kubectl logs -n groombook-uat -l job-name=verify-gro2123` | Pod reaches `Completed` state; logs show `✓ Acquired seed advisory lock` and `✓ Released seed advisory lock` from `seed.ts`; no `PostgresError: … violates foreign key constraint "invoice_tip_splits_invoice_id_invoices_id_fk"` (code 23503); final counts unchanged (500 clients, ~4000 invoices) |
+| TC-API-3.30 | Verify `reset-demo-data` CronJob is schema-safe — TRUNCATE only, no DDL drops (GRO-2722) | 1. Trigger: `kubectl -n groombook-uat create job --from=cronjob/reset-demo-data reset-verify-$(date +%s) --dry-run=client -o name \| xargs kubectl -n groombook-uat apply -f -` or simply `kubectl -n groombook-uat create job --from=cronjob/reset-demo-data reset-verify-$(date +%s)`. 2. Wait for job completion: `kubectl -n groombook-uat wait job/reset-verify-<ts> --for=condition=complete --timeout=300s`. 3. Check logs: `kubectl -n groombook-uat logs job/reset-verify-<ts>`. 4. Verify schema survival: `kubectl -n groombook-uat exec deploy/api -- psql $DATABASE_URL -c "\dt public.*"` and `kubectl -n groombook-uat exec deploy/api -- psql $DATABASE_URL -c "\dt drizzle.*"`. 5. Verify readyz: `curl -s https://uat.groombook.dev/api/readyz` | Job reaches `Completed` (exit 0); logs show `✓ All public tables truncated, sequences reset` — no `DROP TABLE`/`DROP TYPE`/`DROP SCHEMA` in output; all `public.*` tables still present after reset; `drizzle.__drizzle_migrations` still populated (row count unchanged); `https://uat.groombook.dev/api/readyz` returns HTTP 200; demo data reseeded (500 clients visible via GET /api/clients) |
 
 ### 4.4 Appointment Scheduling