diff --git a/templates/claper/.felhom.yml b/templates/claper/.felhom.yml
index 910b37b..2776991 100644
--- a/templates/claper/.felhom.yml
+++ b/templates/claper/.felhom.yml
@@ -10,7 +10,7 @@ subdomain: "present"
 slug: "claper"
 # catalog_since: the date THIS repo last changed this app's pinned images. Any commit that
 # changes an image: line must set this to the same day (see CLAUDE.md).
-catalog_since: "2026-07-18"
+catalog_since: "2026-09-28"
 
 # --- Resource hints (displayed on deploy screen) ---
 resources:
@@ -102,3 +102,9 @@ i18n:
         label: 'Database password'
       - env_var: SECRET_KEY_BASE
         label: 'Encryption key'
+
+# update_ladder — the test record: one tested step per line, oldest first (JSON flow mappings,
+# `09-update-architecture.md` §6.4 part 4). WRITTEN BY scripts/upgrade-test.py, never by hand;
+# gated by scripts/check-test-record.py. An image: move without a proven entry here is refused.
+update_ladder:
+  - {"from": {"claper": "ghcr.io/claperco/claper:2.5", "claper-postgres": "postgres:16-alpine"}, "to": {"claper": "ghcr.io/claperco/claper:2.5", "claper-postgres": "postgres:17-alpine"}, "digest": {"claper": "sha256:4f733dc50b0c77517db402541f88c5489d4c9eedb32ac6c5eef7cadd8a594196", "claper-postgres": "sha256:b0f9560a2de083e2cc7382e75f808c7381a32852a7ec49117deedb300e552b24"}, "verdict": "proven", "tested_at": "2026-09-28T08:52:08Z", "harness_version": 4, "evidence": "felhom.eu/documentation/audits/pg-calcom-claper-2026-09-28/bench/apps/claper/bench/evidence/MV-claper/verdict.json", "box_evidence": "felhom.eu/documentation/audits/pg-calcom-claper-2026-09-28/box/claper/box-verdict-claper.json", "memory_peak_pct": 48.1, "marks": {"files_may_change": false, "needs_person": null, "memory_tight": false}, "memory_basis": "anon", "memory_cgroup_peak_pct": 78.3, "engine_conversion": {"service": "claper-postgres", "engine": "postgres", "from": 16, "to": 17}}
diff --git a/templates/claper/docker-compose.yml b/templates/claper/docker-compose.yml
index 92638ce..e0931e7 100644
--- a/templates/claper/docker-compose.yml
+++ b/templates/claper/docker-compose.yml
@@ -44,7 +44,7 @@ services:
       - "traefik.http.services.claper.loadbalancer.server.port=4000"
 
   claper-postgres:
-    image: postgres:16-alpine
+    image: postgres:17-alpine
     container_name: claper-postgres
     restart: unless-stopped
     environment: