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>

firmware/panel/ws2812_led.cpp

@@ -0,0 +1,39 @@
+/* C API wrapper around ForsakenNGS/Pico_WS2812 */
+
+#include "ws2812_led.h"
+
+#include "WS2812.hpp"
+
+#include "hardware/pio.h"
+#include "pico/stdlib.h"
+
+static WS2812 *s_strip;
+
+extern "C" void ws2812_init(unsigned int pin, unsigned int num_leds) {
+    uint sm = pio_claim_unused_sm(pio0, true);
+    s_strip = new WS2812(pin, num_leds, pio0, sm, WS2812::FORMAT_GRB);
+}
+
+extern "C" void ws2812_set_rgb(const uint8_t *rgb, unsigned int count) {
+    if (s_strip == nullptr || rgb == nullptr) {
+        return;
+    }
+    for (unsigned int i = 0; i < count; i++) {
+        s_strip->setPixelColor(i, rgb[i * 3 + 0], rgb[i * 3 + 1], rgb[i * 3 + 2]);
+    }
+}
+
+extern "C" void ws2812_fill(uint8_t r, uint8_t g, uint8_t b) {
+    if (s_strip == nullptr) {
+        return;
+    }
+    s_strip->fill(WS2812::RGB(r, g, b));
+}
+
+extern "C" void ws2812_show(void) {
+    if (s_strip == nullptr) {
+        return;
+    }
+    s_strip->show();
+    sleep_us(300);
+}