Add ArtNetDMX Pico W firmware with dual DMX and docs.

Art-Net to two RS-485 outputs over Wi-Fi (AP or STA with SoftAP fallback), web UI, mDNS, and QLC+/ArtPoll notes for unicast on STA.

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

lwipopts.h

@@ -0,0 +1,37 @@
+#ifndef _LWIPOPTS_H
+#define _LWIPOPTS_H
+
+#include "lwipopts_examples_common.h"
+
+#undef MEM_SIZE
+#define MEM_SIZE 16000
+#undef MEMP_NUM_TCP_SEG
+#define MEMP_NUM_TCP_SEG 48
+#undef PBUF_POOL_SIZE
+#define PBUF_POOL_SIZE 32
+
+/*
+ * Default MEMP_NUM_UDP_PCB is 4 — not enough for concurrent SoftAP DHCP
+ * server + STA DHCP client + Art-Net (ANY/AP/STA) + mDNS. STA then sticks
+ * at CYW43_LINK_NOIP with dhcp_start() returning ERR_MEM (-1).
+ */
+#undef MEMP_NUM_UDP_PCB
+#define MEMP_NUM_UDP_PCB 12
+
+/* mDNS + DHCP server + dual netif (AP+STA) need extra sys_timeout slots.
+ * Too-small MEMP_NUM_SYS_TIMEOUT panics when a SoftAP client joins (DHCP). */
+#define LWIP_MDNS_RESPONDER 1
+#define LWIP_IGMP 1
+#define LWIP_NUM_NETIF_CLIENT_DATA 1
+#define MDNS_RESP_USENETIF_EXTCALLBACK 1
+#undef MEMP_NUM_SYS_TIMEOUT
+#define MEMP_NUM_SYS_TIMEOUT (LWIP_NUM_SYS_TIMEOUT_INTERNAL + 16)
+
+/* Allow Art-Net UDP bind on AP IP + STA IP + ANY (same port). */
+#define SO_REUSE 1
+
+/* Art-Net discovery uses directed / limited broadcast. */
+#define IP_SOF_BROADCAST 1
+#define IP_SOF_BROADCAST_RECV 1
+
+#endif