Show ZFS pool layout, scrub status and device health in Storage view

/api/storage now runs a single `zpool status -j --json-int -P` (OpenZFS
2.3+) for all pools and returns, per pool:
- top-level vdevs with type, raidz/draid parity, class (data, special,
  dedup, log, cache, spare), state and read/write/checksum errors
- member devices with path, resolved base disk, state, error counters,
  slow I/Os, and the spare-N/replacing-N they sit under while swapping
- scrub/resilver status (progress only while running), the pool's
  status/action text and data-error count
- fragmentation, capacity and dedup ratio from `zpool list`

This replaces the per-pool `zpool status` text loop whose result
(zfs_disks) was never used. Member paths (by-id, by-partlabel, wwn) are
resolved to base disks via sysfs rather than an lsblk call per device.
On ZFS without `-j`, pools report details_available: false and the UI
falls back to the existing basic card.

The ZFS pool card shows a layout summary (e.g. "RAIDZ2 | 5 disks |
Scrub finished ...") and opens a details dialog with the vdev tree,
per-device error counts, scrub/resilver progress, and links from each
member disk to its disk details dialog.

Tested against `zpool status -j` output from PVE 9 / OpenZFS 2.4.4:
mirror, raidz2, striped mirrors, single-disk pool, and a file-backed
degraded raidz1 with log, cache and spare devices.

Tests cover the `zpool status -j` -> Storage view shape against real
output from PVE 9 / OpenZFS 2.4.4 hosts (serials and WWNs replaced):
mirror, raidz2, single-disk pool, slow I/Os, and a degraded raidz1 with
log, cache and spare devices; plus a synthetic resilver with a spare
swapping in. Member path -> base disk resolution is tested against a
stubbed sysfs.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

AppImage/scripts/tests/fixtures/zpool_status_single_rpool.json

@@ -0,0 +1,69 @@
+{
+ "output_version": {
+  "command": "zpool status",
+  "vers_major": 0,
+  "vers_minor": 1
+ },
+ "pools": {
+  "rpool": {
+   "name": "rpool",
+   "state": "ONLINE",
+   "txg": 38071404,
+   "spa_version": 5000,
+   "zpl_version": 5,
+   "scan_stats": {
+    "function": "SCRUB",
+    "state": "FINISHED",
+    "start_time": 1791674641,
+    "end_time": 1791674884,
+    "to_examine": 36167286784,
+    "examined": 36193234944,
+    "skipped": 6365184,
+    "processed": 0,
+    "errors": 0,
+    "bytes_per_scan": 0,
+    "pass_start": 1791909484,
+    "scrub_pause": 0,
+    "scrub_spent_paused": 0,
+    "issued_bytes_per_scan": 0,
+    "issued": 36186869760
+   },
+   "vdevs": {
+    "rpool": {
+     "name": "rpool",
+     "vdev_type": "root",
+     "class": "normal",
+     "state": "ONLINE",
+     "alloc_space": 37495803904,
+     "total_space": 476741369856,
+     "def_space": 476741369856,
+     "read_errors": 0,
+     "write_errors": 0,
+     "checksum_errors": 0,
+     "vdevs": {
+      "/dev/disk/by-id/ata-Patriot_Burst_00000000000000000001-part3": {
+       "name": "/dev/disk/by-id/ata-Patriot_Burst_00000000000000000001-part3",
+       "vdev_type": "disk",
+       "path": "/dev/disk/by-id/ata-Patriot_Burst_00000000000000000001-part3",
+       "class": "normal",
+       "state": "ONLINE",
+       "alloc_space": 37495803904,
+       "total_space": 476741369856,
+       "def_space": 476741369856,
+       "rep_dev_size": 476746088448,
+       "phys_space": 479565971456,
+       "read_errors": 0,
+       "write_errors": 0,
+       "checksum_errors": 0,
+       "slow_ios": 0,
+       "guid": 1001
+      }
+     },
+     "guid": 1001
+    }
+   },
+   "error_count": 0,
+   "pool_guid": 1000
+  }
+ }
+}