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>

iso/builder/config/bootloaders/grub-pc/grub.cfg

@@ -29,6 +29,10 @@ menuentry "EASY-BEE (fail-safe)" {
     initrd  @INITRD_LIVE@
 }
 
+menuentry "Memory Test (memtest86+)" {
+    linux16 /boot/memtest86+.bin
+}
+
 if [ "${grub_platform}" = "efi" ]; then
     menuentry "UEFI Firmware Settings" {
         fwsetup