Dim LED ring, add blink mode, and signal OTA outcome on the ring.

Default brightness is ~5%; UART blink mode and green/red pulses mark OTA success or failure. Failed UART uploads skip ESP-NOW distribution.

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

main/led_ring.h

@@ -1,10 +1,17 @@
+#ifndef LED_RING_H
+#define LED_RING_H
+
 #include <stdint.h>
 
+/** Default RGB scale (~5 % of full brightness). */
+#define LED_RING_DEFAULT_INTENSITY 13
+
 typedef enum {
   LED_CMD_CLEAR,
   LED_CMD_SET_DIGIT,
   LED_CMD_SET_COLOR,
-  LED_CMD_PROGRESS
+  LED_CMD_PROGRESS,
+  LED_CMD_BLINK
 } led_mode_t;
 
 typedef struct {
@@ -13,7 +20,23 @@ typedef struct {
   uint8_t r, g, b;
   uint8_t intensity;
   uint8_t progress;
+  uint16_t blink_ms;
+  uint8_t blink_count;
 } led_command_t;
 
 void led_ring_send_command(led_command_t *cmd);
 void led_ring_init(void);
+
+void led_ring_scale_rgb(uint8_t *r, uint8_t *g, uint8_t *b, uint8_t intensity);
+
+/** OTA feedback: ring fill 0–100 % with RGB. */
+void led_ring_show_ota_progress(uint32_t bytes_done, uint32_t total_bytes,
+                                uint8_t r, uint8_t g, uint8_t b);
+void led_ring_show_ota_clear(void);
+
+/** Single pulse on the full ring (blocking in LED task). */
+void led_ring_blink_once(uint8_t r, uint8_t g, uint8_t b);
+void led_ring_ota_success(void);
+void led_ring_ota_failed(void);
+
+#endif