R-528: the 30-s OOM scan also reads the host's per-container kernel counter (agent GET /guest/oom-kills)

A count above 0 in a running container's current run fires the existing app_oom line (source cgroup/docker in the
details), whatever Docker's OOMKilled says. Old agent: 404 back-off; no agent: Docker's flag only.
Tests TestR528_* red first / red-proved. Commit only.

CHANGELOG.md

@@ -31,6 +31,15 @@ night report (`audits/night-2026-10-28/`).
   `api.escrow.confirm_store_unknown` („Nem tudjuk biztosan… Őrizd meg mindkét kódot…", hu + en) and never promises the
   previous code. `TestR1151_ConfirmAnswersInTheBoxLanguage`'s status-0 case changes with it, on purpose. Tests
   `TestR1254_*` (agentapi, web), red before the fix.
+- **R-528 — the OOM line sees a kill Docker does not report (felhom.eu R-528; agent `GET /guest/oom-kills`).** The
+  30-s dead-app scan (`stacks.ScanOOMKilled`) now also asks the host's agent once per scan for the kernel's per-container
+  `oom_kill` counter (`agentapi.GuestOOMKills`, wired in `cmd/controller/hostoom_wiring.go`, 5 s cap). A running
+  container whose current run has a count above 0 is an OOM kill whatever Docker's `OOMKilled` says: the existing
+  `app_oom` line (once per run, R-514/R-636) fires, its details carry `source` (`docker`, `cgroup` or `docker,cgroup`),
+  and the host's count is the run's kill count. An agent without the route (404) is asked again only after 10 minutes
+  and said once; no agent (9202) = Docker's flag only, as before. The inspect now reads `{{.Id}}` too. Tests
+  `TestR528_*` (stacks, cmd/controller), red before the fix (the host-counted kill was not seen) or red-proved by
+  mutation (the back-off, the wiring).
 - **H8 — `internal/backup/restore_copy_sweep.go`:** an unused restore copy goes after 14 days. Every 6 hours
   (`restore-copy-sweep`) a copy is removed only when the app has no restore hold of any kind, the app-stop marker is
   readable and does not name the app, no restore runs, and the copy is older than 14 days. Tests `TestR1256_H8_*`