feat: close #54 V2 install safety, #33 rofi scrollbar, #43 MOTD tip

#54: permanent checks.installer-safety; test-install-safety harness with
offline compose-fail, LUKS-signature disk warn, and HM-hint FORCE paths.
#33: enable themed rofi scrollbars (generated + all whole-swap .rasi).
#43: MOTD + first-boot tip for System › Firmware (V3 LVFS stays hw-queue).

V2: compose-fail/disk-warn/hm-hint logs green offline; theme-shot
boreal+summer-night menus OK. V0 flake/installer-safety.

pkgs/nomarchy-control-center/nomarchy-control-center.sh

@@ -39,6 +39,11 @@ function first_boot() {
         fi
     fi
     
+    if command -v fwupdmgr >/dev/null 2>&1; then
+        gum style --foreground 245 \
+            "Tip: SUPER+M → System › Firmware checks LVFS updates (never auto-flashes)."
+    fi
+
     gum style --foreground 212 "First boot configuration complete!"
     echo "You can always change these later in the Control Center."
     read -r -n 1 -s -p "Press any key to exit..."