detect_platform: %q-escape output so eval survives spaces in MODEL

The Jetson model string has spaces; emitted unquoted, eval ran its second word
as a command ("Jetson: command not found"). printf %q makes the output safe to
eval, which is how every other script consumes it.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

scripts/detect_platform.sh

@@ -49,9 +49,12 @@ case "$major" in
     *)  jetpack="unknown" ;;
 esac
 
-echo "L4T=${l4t:-unknown}"
+# %q-escaped so a caller can `eval` the output safely: MODEL holds spaces
-echo "L4T_MAJOR=${major:-unknown}"
+# ("NVIDIA Jetson Orin Nano …"), which unquoted would make eval run "Jetson" as a
-echo "JETPACK=${jetpack}"
+# command.
-echo "SOC=${soc}"
+printf 'L4T=%q\n'       "${l4t:-unknown}"
-echo "ARCH=$(uname -m)"
+printf 'L4T_MAJOR=%q\n' "${major:-unknown}"
-echo "MODEL=${model}"
+printf 'JETPACK=%q\n'   "${jetpack}"
+printf 'SOC=%q\n'       "${soc}"
+printf 'ARCH=%q\n'      "$(uname -m)"
+printf 'MODEL=%q\n'     "${model}"