Add multi-panel Pico UDP firmware and Python LED control.

Pico panels get static IPs on 10.1.1.10–14 with per-panel LED counts, Makefile deploy targets, and Python examples for animations, sync tests, and direct Pi SPI control.

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/stop_ap.sh

@@ -0,0 +1,62 @@
+#!/usr/bin/env bash
+# Stop the portal access point and return wlan0 to WiFi client mode.
+
+set -euo pipefail
+
+CON_NAME="${PORTAL_AP_CON_NAME:-portal-ap}"
+WLAN_IF="${PORTAL_AP_IF:-wlan0}"
+
+if [[ "${EUID}" -ne 0 ]]; then
+    echo "Error: run as root: sudo $0" >&2
+    exit 1
+fi
+
+if ! command -v nmcli >/dev/null; then
+    echo "Error: NetworkManager (nmcli) is required" >&2
+    exit 1
+fi
+
+if nmcli -t -f NAME connection show | grep -Fxq "${CON_NAME}"; then
+    nmcli connection down "${CON_NAME}" 2>/dev/null || true
+    nmcli connection modify "${CON_NAME}" connection.autoconnect no
+    echo "Access point '${CON_NAME}' stopped (autoconnect disabled)."
+else
+    echo "Connection '${CON_NAME}' not found."
+fi
+
+rfkill unblock wifi >/dev/null 2>&1 || true
+nmcli radio wifi on >/dev/null 2>&1 || true
+nmcli device disconnect "${WLAN_IF}" 2>/dev/null || true
+nmcli device wifi rescan 2>/dev/null || true
+sleep 2
+
+# Saved client profiles, newest first (skip the AP connection).
+mapfile -t CLIENT_CONS < <(
+    nmcli -t -f NAME,TYPE,TIMESTAMP connection show | awk -F: -v ap="${CON_NAME}" '
+        $2 == "802-11-wireless" && $1 != ap { print $3 "\t" $1 }
+    ' | sort -rn | cut -f2
+)
+
+CONNECTED=0
+for client_con in "${CLIENT_CONS[@]}"; do
+    key_mgmt="$(nmcli -g 802-11-wireless-security.key-mgmt connection show "${client_con}" 2>/dev/null || true)"
+    if [[ -z "${key_mgmt}" ]]; then
+        echo "Skipping '${client_con}': missing 802-11-wireless-security.key-mgmt."
+        echo "  Fix: sudo nmcli connection delete ${client_con}"
+        echo "       sudo nmcli device wifi connect <SSID> password <pass>"
+        continue
+    fi
+    if nmcli connection up "${client_con}" ifname "${WLAN_IF}" 2>/dev/null; then
+        echo "wlan0 connected as client: ${client_con}"
+        CONNECTED=1
+        break
+    fi
+done
+
+if ((CONNECTED == 0)); then
+    echo "wlan0 is in client mode but no saved network connected."
+    echo "List networks: nmcli device wifi list"
+    echo "Connect:       sudo nmcli device wifi connect <SSID> password <pass>"
+fi
+
+echo "Remove AP permanently: sudo nmcli connection delete ${CON_NAME}"