Send ESP-NOW accel only on deadzone change and harden BLE+WiFi OTA coex.

Quiet pods no longer spam 100 Hz samples; mute wifi logs and throttle BLE
notifies during slave distribution so the wifi task stack does not panic.

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

main/esp_now_slave.c

@@ -26,7 +26,8 @@
 /** While master or slave OTA is in progress (discover may be sparse). */
 #define SLAVE_MASTER_OTA_GRACE_MS 300000u
 /**
- * Accel stream cadence (10 ms frame). TX path is selectable (INPUT_SEND_MODE).
+ * Accel stream poll cadence (10 ms frame). TX only when sample exceeds the
+ * BMA456 deadzone vs last sent sample. TX path is selectable (INPUT_SEND_MODE).
  * With master Discover.master_time_us, slaves phase into 1 ms slots:
  * offset_ms = (assigned_id - 1) % 8. Slot wait uses esp_timer (FreeRTOS tick
  * is 10 ms — too coarse for intra-frame offsets).
@@ -516,6 +517,9 @@ static void handle_accel_stream(const uint8_t *master_mac,
     return;
   }
   s_accel_stream_enabled = cfg->enable;
+  if (cfg->enable) {
+    bma456_accel_stream_reset_baseline();
+  }
   char mac_str[18];
   esp_now_core_mac_to_str(master_mac, mac_str, sizeof(mac_str));
   ESP_LOGI(TAG, "accel stream %s from master %s (id=%lu)",
@@ -743,7 +747,8 @@ static void accel_stream_task(void *param) {
   (void)param;
 
   ESP_LOGI(TAG,
-           "accel stream task (interval %u ms, %u×%llu us slots, mode selectable)",
+           "accel stream task (poll %u ms, deadzone TX, %u×%llu us slots, "
+           "mode selectable)",
            (unsigned)ESPNOW_ACCEL_INTERVAL_MS, (unsigned)ESPNOW_ACCEL_SLOT_COUNT,
            (unsigned long long)ESPNOW_ACCEL_SLOT_US);
 
@@ -759,6 +764,9 @@ static void accel_stream_task(void *param) {
     if (bma456_read_accel(&x, &y, &z) != ESP_OK) {
       continue;
     }
+    if (!bma456_accel_stream_take_if_changed(x, y, z)) {
+      continue;
+    }
     (void)send_accel_sample(s_master_mac, s_assigned_id, x, y, z);
   }
 }