# REPORT — slice 9 (controller half): host-health view (v0.39.0) (2026-06-10)

> Overwrite-latest report. Cumulative history: [CHANGELOG.md](CHANGELOG.md).

## What was implemented

The customer-facing half of **slice 9**. Pairs with `felhom-agent` v0.14.0. The de-privileged
controller (slice 8C) sees only its own cgroup, so it can't read the host. The monitoring page now
shows the **real Proxmox box**, proxied from the agent's new `GET /host/metrics`.

### `internal/agentapi` — client method
- **`Client.HostMetrics(ctx)`** — calls the agent's `GET /host/metrics` over the leaf-pinned,
  per-guest-token channel (same client as the 8C disk proxy). New mirror structs `HostMetrics` (with
  nullable `CPUTempC`), `StorageTarget`, `ThinPoolFill`, `SmartSummary` (a **subset** — only the
  fields the UI renders; unknown wire keys ignored).

### `internal/web` — proxy + UI
- **`ServeHostMetricsAPI`** (`agent_host_metrics_handler.go`) — a thin read-only proxy:
  `GET /api/host-metrics` → agent `GET /host/metrics`. Returns the `{ok,data,error}` envelope; 503
  when the local API is not configured (unprovisioned guest), 502 on an agent error. Wired in
  `main.go` behind `RequireAuth` (GET-only → no CSRF wrapper).
- **Monitoring view** (`templates/monitoring.html`): a new **"Szerver állapota (gazdagép)"** card at
  the top renders the host block (CPU% + load, memory used/total, **CPU temp** or **"n/a"** when
  null, uptime) + per-storage capacity bars (used/total, thin-pool fill, disk temp/wear), reusing
  the existing `system-bar`/`storage-item` styling. Polls `/api/host-metrics` every **8 s** while the
  page is open (a live snapshot, distinct from the controller's own 60 s charts); yellow "nem
  elérhető" banner when the agent is unreachable.

## Tests (green)
- `agentapi/host_metrics_test.go`: decodes host + storage (thin-pool, SMART temp + NVMe wear), USB
  drive's null SMART, and a null `cpu_temp_c` → nil pointer.
- `go build ./...` + `go test ./internal/agentapi ./internal/web` green.

## Versioning / docs
- Version `0.38.0 → 0.39.0` (set at build via ldflags); `CHANGELOG.md` + `controller/README.md`
  (Monitoring → "Host (Proxmox box) Health" section) updated.

## Pending
- **Build + deploy** controller v0.39.0 to the demo nodes and live-validate the monitoring page
  against the real N100 (cross-check vs `pvesh`/`free`/`df`).