Handle NVIDIA GSP firmware init hang with timeout fallback

- bee-nvidia-load: run insmod in background, poll /proc/devices for
  nvidiactl; if GSP init doesn't complete in 90s, kill insmod and retry
  with NVreg_EnableGpuFirmware=0. Handles EBUSY case with clear error.
- Write /run/bee-nvidia-mode (gsp-on/gsp-off/gsp-stuck) for audit layer
- Show GSP mode badge in sidebar: yellow for gsp-off, red for gsp-stuck
- Report NvidiaGSPMode in RuntimeHealth with issue entries
- Simplify GRUB menu: default (KMS+GSP), advanced submenu (GSP=off,
  nomodeset, fail-safe), remove load-to-RAM entry
- Add pcmanfm, ristretto, mupdf, mousepad to desktop packages

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

audit/internal/platform/runtime.go

@@ -173,6 +173,22 @@ func (s *System) collectGPURuntimeHealth(vendor string, health *schema.RuntimeHe
 
 	switch vendor {
 	case "nvidia":
+		if raw, err := os.ReadFile("/run/bee-nvidia-mode"); err == nil {
+			health.NvidiaGSPMode = strings.TrimSpace(string(raw))
+			if health.NvidiaGSPMode == "gsp-stuck" {
+				health.Issues = append(health.Issues, schema.RuntimeIssue{
+					Code:        "nvidia_gsp_stuck",
+					Severity:    "critical",
+					Description: "NVIDIA GSP firmware init timed out and the kernel module is stuck. Reboot and select 'GSP=off' in the boot menu.",
+				})
+			} else if health.NvidiaGSPMode == "gsp-off" {
+				health.Issues = append(health.Issues, schema.RuntimeIssue{
+					Code:        "nvidia_gsp_disabled",
+					Severity:    "warning",
+					Description: "NVIDIA GSP firmware disabled (fallback). Power management runs via CPU path — power draw readings may differ from reference hardware.",
+				})
+			}
+		}
 		health.DriverReady = strings.Contains(lsmodText, "nvidia ")
 		if !health.DriverReady {
 			health.Issues = append(health.Issues, schema.RuntimeIssue{