feat: task queue, UI overhaul, burn tests, install-to-RAM

- Task queue: all SAT/audit jobs enqueue and run one-at-a-time;
  tasks persist past page navigation; new Tasks page with cancel/priority/log stream
- UI: consolidate nav (Validate, Burn, Tasks, Tools); Audit becomes modal;
  Dashboard hardware summary badges + split metrics charts (load/temp/power);
  Tools page consolidates network, services, install, support bundle
- AMD GPU: acceptance test and stress burn cards; GPU presence API greys
  out irrelevant SAT cards automatically
- Burn tests: Memory Stress (stress-ng --vm), SAT Stress (stressapptest)
- Install to RAM: copies squashfs to /dev/shm, re-associates loop devices
  via LOOP_CHANGE_FD ioctl so live media can be ejected
- Charts: relative time axis (0 = now, negative left)
- memtester: LimitMEMLOCK=infinity in bee-web.service; empty output → UNSUPPORTED
- SAT overlay applied dynamically on every /audit.json serve
- MIME panic guard for LiveCD ramdisk I/O errors
- ISO: add memtest86+, stressapptest packages; memtest86+ GRUB entry;
  disable screensaver/DPMS in bee-openbox-session
- Unknown SAT status severity = 1 (does not override OK)

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

audit/internal/app/sat_overlay.go

@@ -141,9 +141,11 @@ func satSummaryStatus(summary satSummary, label string) (string, string, bool) {
 func satKeyStatus(rawStatus, label string) (string, string, bool) {
 	switch strings.ToUpper(strings.TrimSpace(rawStatus)) {
 	case "OK":
-		return "OK", label + " passed", true
+		// No error description on success — error_description is for problems only.
+		return "OK", "", true
 	case "PARTIAL", "UNSUPPORTED", "CANCELED", "CANCELLED":
-		return "Warning", label + " incomplete", true
+		// Tool couldn't run or test was incomplete — we can't assert hardware health.
+		return "Unknown", "", true
 	case "FAILED":
 		return "Critical", label + " failed", true
 	default:
@@ -180,6 +182,8 @@ func statusSeverity(status string) int {
 		return 2
 	case "OK":
 		return 1
+	case "Unknown":
+		return 1 // same as OK — does not override OK from another source
 	default:
 		return 0
 	}