v0.64.0: additive storage discovery (A1) + internal-SSD label (A2)

A1: AutoDiscoverStoragePaths no longer bails on a non-empty registry;
registers only deployed-app paths missing from the registry. Never
mutates/removes existing entries, never re-adds or reactivates a path
present in ANY state (incl. Decommissioned), never flips IsDefault.
A2: InferStorageLabel maps base==felhom-data namespace dir to
'Belső SSD (rendszer)' to disambiguate the internal system volume.
Table-driven tests incl. a companion that fails without the
skip-by-presence guard.

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

CHANGELOG.md

@@ -1,5 +1,32 @@
 ## Changelog
 
+### v0.64.0 — storage-lifecycle cleanups (2026-06-14)
+
+Two settings-layer cleanups from the F9 storage-registration diagnosis
+(`felhom.eu/documentation/backlog/DIAGNOSIS-f9-storage-registration-gap-2026-06-14.md`), trunk-based on
+`main`, each with table-driven tests that fail on the pre-fix code.
+
+- **A1 — `AutoDiscoverStoragePaths` is now ADDITIVE** (`internal/settings/settings.go`). It previously bailed
+  early (`if len(s.StoragePaths) > 0 { return }`), so a drive a deployed app referenced but that was missing
+  from the registry was never picked up after first run. It now registers only the discovered paths NOT
+  already present, while honouring strict invariants: never removes/modifies a manually-added path; SKIPS any
+  path already in the registry IN ANY STATE — including a `Decommissioned` soft-marked entry — so it can't
+  re-add or reactivate it; never flips `IsDefault` (a newly-discovered path becomes default ONLY if the
+  registry currently has no default at all, and only the first such new path). NOT auto-register-on-attach —
+  it only picks up paths deployed apps already reference (that recommendation was rejected; manual enrollment
+  is by design). New `internal/settings/storage_discovery_test.go` covers it, incl. a companion test that
+  FAILS if the skip-by-presence guard is removed (verified: removing the guard re-adds the decommissioned
+  path).
+- **A2 — internal-SSD label disambiguation** (`InferStorageLabel`, `internal/settings/settings.go`). A path
+  whose basename is the `felhom-data` namespace dir (the internal system volume, e.g.
+  `/mnt/sys_drive/felhom-data`) previously labelled as `Tárhely (felhom-data)`, colliding with the per-drive
+  felhom-data namespace. It now reads **`Belső SSD (rendszer)`**. Discriminator is `base ==
+  appbackup.FelhomDataDir`; Model-A user drives register their MOUNT ROOT (e.g. `/mnt/felhom-usb`), never
+  `.../felhom-data`, so this can't mislabel a user drive. Still overridable via `SetStorageLabel`. The demo's
+  already-seeded `settings.json` label for that path on guest 9201 was updated out-of-band (the seeded value
+  doesn't auto-change). Separate host-metrics label in `web/agent_host_metrics_handler.go` was intentionally
+  left untouched.
+
 ### v0.63.0 — reflect agent F9/F20-BUG2 disk fields (2026-06-14)
 
 Pass through two new fields the host agent (v0.31.0) now returns on `/disks`, so they reach