hub v0.7.2: ingest agent storage_targets (slice 5 Phase A)

Accept + persist the now-populated host-report storage_targets. Minimal — the
authoritative storage manifest is hub-owned (slice 10); this mirrors what the agent
observes.

- hostReportPayload.StorageTargets: full mirror of the agent's hub.StorageTarget
  wire contract; persisted verbatim in report_json (no schema change); count +
  WARN on disconnected targets.
- shared host-report golden updated with two populated targets; byte-identical with
  felhom-agent's copy.
- TestHostStorageTarget_GoldenContract: hub half of the bidirectional key-set test.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

hub/CHANGELOG.md

@@ -1,5 +1,29 @@
 # Felhom Hub — Changelog
 
+## v0.7.2 — ingest agent storage_targets (slice 5 Phase A) (2026-06-09)
+
+The agent's slice-5 work populates the host-report's `storage_targets` (previously empty).
+This is the hub half: accept + persist them. Minimal by design — the rich, authoritative
+storage manifest (desired class/role/policy/creds) is hub-owned and lands at slice 10; this
+slice only mirrors what the agent observes.
+
+### Added
+- **`hostReportPayload.StorageTargets`** (`internal/api/handler.go`) — a full mirror of the
+  agent's `hub.StorageTarget` wire contract (name/type/durable_id/state/reachable/usage/
+  content/mount/class_hint/role/`thin_pool`/`smart`). The targets are persisted verbatim in
+  the existing `report_json` row (no schema change); the handler counts them and logs a
+  `[WARN]` when any are `disconnected` (the storage analog of host-down visibility).
+- **`testdata/host-report.golden.json`** — updated to carry two populated `storage_targets`
+  (an lvmthin with `thin_pool`, a usb), kept **byte-identical** with felhom-agent's copy.
+- **`TestHostStorageTarget_GoldenContract`** — the hub half of the bidirectional key-set test:
+  round-trips the golden's `storage_targets[0]` through the mirror struct and asserts the key
+  set matches exactly (no missing/extra fields vs the agent). `TestHostReport_GoldenContract`
+  also now asserts the targets are persisted + parse back.
+
+### Notes
+- Backward-compatible: an older agent that sends `storage_targets: []` (or omits it) is
+  accepted unchanged. The legacy controller report path is untouched (frozen until slice 10).
+
 ## Repo docs — no hub version change (2026-06-08)
 
 ### Changed