Add USB export drive and LiveCD-in-RAM checks to Runtime Health

- schema: add ToRAMStatus and USBExportPath fields to RuntimeHealth
- platform/runtime.go: collectToRAMHealth (ok/warning/failed based on
  IsLiveMediaInRAM + toramActive) and collectUSBExportHealth (scans
  /proc/mounts + lsblk for writable USB-backed filesystems)
- pages.go: add USB Export Drive and LiveCD in RAM rows to the health table

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

audit/internal/platform/runtime.go

@@ -1,6 +1,7 @@
 package platform
 
 import (
+	"bufio"
 	"os"
 	"os/exec"
 	"strings"
@@ -114,6 +115,8 @@ func (s *System) CollectRuntimeHealth(exportDir string) (schema.RuntimeHealth, e
 	}
 
 	s.collectGPURuntimeHealth(vendor, &health)
+	s.collectToRAMHealth(&health)
+	s.collectUSBExportHealth(&health)
 
 	if health.Status != "FAILED" && len(health.Issues) > 0 {
 		health.Status = "PARTIAL"
@@ -168,6 +171,90 @@ func resolvedToolStatus(display string, candidates ...string) ToolStatus {
 	return ToolStatus{Name: display}
 }
 
+// collectToRAMHealth checks whether the LiveCD ISO has been copied to RAM.
+// Status values: "ok" = in RAM, "warning" = toram not active (no copy attempted),
+// "failed" = toram was requested but medium is not in RAM (copy failed or in progress).
+func (s *System) collectToRAMHealth(health *schema.RuntimeHealth) {
+	inRAM := s.IsLiveMediaInRAM()
+	active := toramActive()
+	switch {
+	case inRAM:
+		health.ToRAMStatus = "ok"
+	case active:
+		// toram was requested but medium is not yet/no longer in RAM
+		health.ToRAMStatus = "failed"
+		health.Issues = append(health.Issues, schema.RuntimeIssue{
+			Code:        "toram_copy_failed",
+			Severity:    "warning",
+			Description: "toram boot parameter is set but the live medium is not mounted from RAM.",
+		})
+	default:
+		health.ToRAMStatus = "warning"
+	}
+}
+
+// collectUSBExportHealth scans /proc/mounts for a writable USB-backed filesystem
+// suitable for log export. Sets USBExportPath to the first match found.
+func (s *System) collectUSBExportHealth(health *schema.RuntimeHealth) {
+	health.USBExportPath = findUSBExportMount()
+}
+
+// findUSBExportMount returns the mount point of the first writable USB filesystem
+// found in /proc/mounts (vfat, exfat, ext2/3/4, ntfs) whose backing block device
+// has USB transport. Returns "" if none found.
+func findUSBExportMount() string {
+	f, err := os.Open("/proc/mounts")
+	if err != nil {
+		return ""
+	}
+	defer f.Close()
+
+	// fs types that are expected on USB export drives
+	exportFSTypes := map[string]bool{
+		"vfat":  true,
+		"exfat": true,
+		"ext2":  true,
+		"ext3":  true,
+		"ext4":  true,
+		"ntfs":  true,
+		"ntfs3": true,
+		"fuseblk": true,
+	}
+
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		// fields: device mountpoint fstype options dump pass
+		fields := strings.Fields(scanner.Text())
+		if len(fields) < 4 {
+			continue
+		}
+		device, mountPoint, fsType, options := fields[0], fields[1], fields[2], fields[3]
+		if !exportFSTypes[strings.ToLower(fsType)] {
+			continue
+		}
+		// Skip read-only mounts
+		opts := strings.Split(options, ",")
+		readOnly := false
+		for _, o := range opts {
+			if strings.TrimSpace(o) == "ro" {
+				readOnly = true
+				break
+			}
+		}
+		if readOnly {
+			continue
+		}
+		// Check USB transport via lsblk on the device
+		if !strings.HasPrefix(device, "/dev/") {
+			continue
+		}
+		if blockDeviceTransport(device) == "usb" {
+			return mountPoint
+		}
+	}
+	return ""
+}
+
 func (s *System) collectGPURuntimeHealth(vendor string, health *schema.RuntimeHealth) {
 	lsmodText := commandText("lsmod")