Theme GRUB graphique tactile pour triple boot

- Fond sombre avec degradé
- Icônes 96x96 pour chaque projet (PB, PS, ?)
- Grosses polices DejaVu pour ecran tactile
- Highlight de selection bleu
- GRUB_TIMEOUT=-1 : attend la selection (pas de timeout)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/grub-theme/theme.txt

@@ -0,0 +1,35 @@
+# Theme GRUB tactile - Triple Boot Terra
+title-text: ""
+desktop-color: "#1a1a2e"
+message-color: "#ffffff"
+message-bg-color: "#000000"
+terminal-font: "DejaVu Sans Bold 24"
+
++ boot_menu {
+  left = 10%
+  top = 15%
+  width = 80%
+  height = 70%
+  item_font = "DejaVu Sans Bold 36"
+  item_color = "#cccccc"
+  selected_item_font = "DejaVu Sans Bold 42"
+  selected_item_color = "#ffffff"
+  item_height = 120
+  item_padding = 20
+  item_spacing = 30
+  item_icon_space = 30
+  icon_width = 96
+  icon_height = 96
+  selected_item_pixmap_style = "select_*.png"
+}
+
++ label {
+  left = 0
+  top = 90%
+  width = 100%
+  height = 30
+  text = "Toucher pour selectionner - Appuyer sur Entree pour demarrer"
+  font = "DejaVu Sans 18"
+  color = "#888888"
+  align = "center"
+}