fix(xfusion): parse disk_info Capacity in TB/binary units for size_gb

parseDiskInfo read capacity with Sscanf(cap, "%f GB"), so every iBMC
"Capacity : 6.986 TB" NVMe line failed to match and size_gb stayed 0
while the BEE-SP live-CD export of the same drive had the real size.
The iBMC number is also binary (GiB/TiB) despite the GB/TB label.

parseDiskCapacityGB parses number + unit (TB/GB/MB), treats it as
binary, and emits decimal GB, matching the drive's marketed capacity
and the live-CD inventory. Found by diffing a G5500 V7 BMC dump against
its live-CD bundle. See ADL-063.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011LffAvostt3uMkiUbVUiyM

internal/parser/vendors/xfusion/parser_test.go

@@ -369,3 +369,55 @@ func TestParseMemInfo_EmbeddedNewlineInBOM(t *testing.T) {
 		t.Errorf("m170 fields not recovered: %+v", m170)
 	}
 }
+
+// TestParseDiskInfo_CapacityUnits guards the disk_info "Capacity" parse: iBMC
+// labels the number "GB"/"TB" but the value is binary, and the old code only
+// matched a literal " GB" so every "X TB" NVMe drive got size_gb 0 while the
+// BEE-SP live-CD export of the same drive reported the real decimal size.
+func TestParseDiskInfo_CapacityUnits(t *testing.T) {
+	cases := []struct {
+		name    string
+		content string
+		wantGB  int
+	}{
+		{
+			name: "kioxia nvme reported as TB",
+			content: "Serial Number : 9F30A0440V43\n" +
+				"Model : KIOXIA KCD8XPUG7T68\n" +
+				"Media Type : SSD\n" +
+				"Interface Type : PCIe\n" +
+				"Capacity : 6.986 TB\n",
+			wantGB: 7680,
+		},
+		{
+			name: "intel sata reported as TB",
+			content: "Serial Number : PHYF202100WK3P8EGN\n" +
+				"Model : INTEL SSDSC2KB038T8\n" +
+				"Capacity : 3.492 TB\n",
+			wantGB: 3840,
+		},
+		{
+			name:    "boot ssd reported as GB",
+			content: "Serial Number : X1\nModel : M\nCapacity : 446.625 GB\n",
+			wantGB:  480,
+		},
+		{
+			name:    "missing capacity",
+			content: "Serial Number : X2\nModel : M\n",
+			wantGB:  0,
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			d := parseDiskInfo([]byte(tc.content))
+			if d == nil {
+				t.Fatal("parseDiskInfo returned nil")
+			}
+			// iBMC reports binary units; a few GB of rounding slack vs the
+			// live-CD's exact byte count is acceptable (size_gb is display-only).
+			if diff := d.SizeGB - tc.wantGB; diff < -2 || diff > 2 {
+				t.Errorf("SizeGB = %d, want ~%d", d.SizeGB, tc.wantGB)
+			}
+		})
+	}
+}