Disks: eMMC is one device, not three, and reports wear from its own registers

mmcblkNboot0/boot1/rpmb are hardware areas of the chip; hide them on Disks and
Dashboard. Badge eMMC/SD instead of SSD. smartctl cannot talk to MMC, so read
life_time and pre_eol_info from /sys instead of showing its error.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

internal/metrics/metrics.go

@@ -573,6 +573,10 @@ func (c *Collector) net(dt float64) []Net {
 var skipDiskPrefix = []string{"loop", "ram", "zram", "nbd", "sr", "fd", "dm-", "md", "drbd", "zd", "pmem"}
 
 func skipDisk(n string) bool {
+	// eMMC boot/RPMB/general-purpose areas: regions of the chip, not drives
+	if strings.HasPrefix(n, "mmcblk") && (strings.Contains(n, "boot") || strings.HasSuffix(n, "rpmb") || strings.Contains(n, "gp")) {
+		return true
+	}
 	for _, p := range skipDiskPrefix {
 		if strings.HasPrefix(n, p) {
 			return true