v0.54.0: format-safety foundation — unclaimed-disk guard + guarded-mkfs wrapper

Impl-1. Format now runs a mandatory unclaimed-disk guard (internal/storage/claim.go:
SystemDisks + lsblk member-FSTYPE + foreign-mount + RO + pvs/zpool; fail-safe →
CLAIMED) before any mkfs — refuses the OS disk / LVM PV / ZFS-mdraid member /
foreign-mounted device even when non-data-bearing (guard sits in Format, not the
handler). Below the agent, mkfs goes ONLY through configs/felhom-mkfs-guarded.sh
(sudoers no longer allowlists raw mkfs.*), which re-checks the catastrophic cases
as root. Read-only pvs/zpool added to FELHOM_DISK. Tests + red-proof; capability
manifest updated. go build/vet/test clean.

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

internal/capability/manifest.go

@@ -57,8 +57,8 @@ var manifest = []Capability{
 	// ---- Disk inspect / format gate (Critical: the data-bearing classifier + format) ----
 	{"disk-blkid", "disk data-bearing classify (format gate)", "/usr/sbin/blkid", []string{"-p", "-o", "export", "/dev/sda"}, true},
 	{"disk-lsblk", "disk topology read (format gate)", "/usr/bin/lsblk", []string{"-J", "-o", "NAME,FSTYPE,PTTYPE,MOUNTPOINT", "/dev/sda"}, true},
-	{"disk-mkfs-ext4", "blank-device format (ext4)", "/usr/sbin/mkfs.ext4", []string{"-F", "/dev/sda"}, true},
-	{"disk-mkfs-xfs", "blank-device format (xfs)", "/usr/sbin/mkfs.xfs", []string{"-f", "/dev/sda"}, false},
+	{"disk-mkfs-ext4", "guarded format (ext4)", "/usr/local/sbin/felhom-mkfs-guarded", []string{"/dev/sda", "ext4"}, true},
+	{"disk-mkfs-xfs", "guarded format (xfs)", "/usr/local/sbin/felhom-mkfs-guarded", []string{"/dev/sda", "xfs"}, false},
 	{"disk-smart", "disk SMART health read", "/usr/sbin/smartctl", []string{"-a", "-j", "/dev/sda"}, false},
 	{"disk-lvs", "thin-pool usage read", "/usr/sbin/lvs", []string{"--reportformat", "json", "--units", "b", "-o", "lv_name,data_percent,metadata_percent", "--", "pve/data"}, false},