Add BMA456 tap detection with ESP-NOW notify and host snapshot API.

Slaves forward configured tap kinds to the master; goTool exposes CLI, dashboard, REST, and WebSocket with separate notify vs receive and 2s display cache.

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

main/client_registry.c

@@ -257,6 +257,31 @@ static void clear_client_accel(client_slot_t *slot) {
   slot->info.accel_updated_at = 0;
 }
 
+static void clear_client_tap(client_slot_t *slot) {
+  if (slot == NULL) {
+    return;
+  }
+  slot->info.tap_valid = false;
+  slot->info.tap_kind = 0;
+  slot->info.tap_updated_at = 0;
+}
+
+static bool tap_kind_enabled(const client_info_t *info, uint32_t kind) {
+  if (info == NULL) {
+    return false;
+  }
+  switch (kind) {
+  case 1:
+    return info->tap_notify_single;
+  case 2:
+    return info->tap_notify_double;
+  case 3:
+    return info->tap_notify_triple;
+  default:
+    return false;
+  }
+}
+
 esp_err_t client_registry_set_accel_stream(uint32_t client_id, bool enabled) {
   for (size_t i = 0; i < CLIENT_REGISTRY_MAX; i++) {
     if (!s_clients[i].active || s_clients[i].info.id != client_id) {
@@ -325,6 +350,124 @@ esp_err_t client_registry_update_accel(const uint8_t mac[CLIENT_MAC_LEN],
   return ESP_OK;
 }
 
+esp_err_t client_registry_set_tap_notify(uint32_t client_id, bool single,
+                                         bool double_tap, bool triple) {
+  for (size_t i = 0; i < CLIENT_REGISTRY_MAX; i++) {
+    if (!s_clients[i].active || s_clients[i].info.id != client_id) {
+      continue;
+    }
+    s_clients[i].info.tap_notify_single = single;
+    s_clients[i].info.tap_notify_double = double_tap;
+    s_clients[i].info.tap_notify_triple = triple;
+    if (!single && !double_tap && !triple) {
+      clear_client_tap(&s_clients[i]);
+    }
+    return ESP_OK;
+  }
+  return ESP_ERR_NOT_FOUND;
+}
+
+esp_err_t client_registry_get_tap_notify(uint32_t client_id, bool *single_out,
+                                         bool *double_tap_out,
+                                         bool *triple_out) {
+  if (single_out == NULL || double_tap_out == NULL || triple_out == NULL) {
+    return ESP_ERR_INVALID_ARG;
+  }
+  const client_info_t *info = client_registry_find_by_id(client_id);
+  if (info == NULL) {
+    return ESP_ERR_NOT_FOUND;
+  }
+  *single_out = info->tap_notify_single;
+  *double_tap_out = info->tap_notify_double;
+  *triple_out = info->tap_notify_triple;
+  return ESP_OK;
+}
+
+size_t client_registry_set_tap_notify_all(bool single, bool double_tap,
+                                          bool triple) {
+  size_t n = 0;
+  for (size_t i = 0; i < CLIENT_REGISTRY_MAX; i++) {
+    if (!s_clients[i].active) {
+      continue;
+    }
+    s_clients[i].info.tap_notify_single = single;
+    s_clients[i].info.tap_notify_double = double_tap;
+    s_clients[i].info.tap_notify_triple = triple;
+    if (!single && !double_tap && !triple) {
+      clear_client_tap(&s_clients[i]);
+    }
+    n++;
+  }
+  return n;
+}
+
+esp_err_t client_registry_update_tap(const uint8_t mac[CLIENT_MAC_LEN],
+                                     uint32_t slave_id, uint32_t kind) {
+  if (mac == NULL || kind < 1 || kind > 3) {
+    return ESP_ERR_INVALID_ARG;
+  }
+
+  client_slot_t *slot = find_slot(mac);
+  if (slot == NULL) {
+    return ESP_ERR_NOT_FOUND;
+  }
+  if (slot->info.id != slave_id) {
+    return ESP_ERR_INVALID_ARG;
+  }
+  if (!tap_kind_enabled(&slot->info, kind)) {
+    return ESP_ERR_INVALID_STATE;
+  }
+
+  slot->info.tap_kind = kind;
+  slot->info.tap_valid = true;
+  slot->info.tap_updated_at = now_ms();
+  return ESP_OK;
+}
+
+void client_registry_expire_tap(client_info_t *info) {
+  if (info == NULL || !info->tap_valid) {
+    return;
+  }
+  if (client_registry_ms_since(info->tap_updated_at) >
+      CLIENT_REGISTRY_TAP_MAX_AGE_MS) {
+    info->tap_valid = false;
+    info->tap_kind = 0;
+    info->tap_updated_at = 0;
+  }
+}
+
+void client_registry_clear_tap(client_info_t *info) {
+  if (info == NULL) {
+    return;
+  }
+  info->tap_valid = false;
+  info->tap_kind = 0;
+  info->tap_updated_at = 0;
+}
+
+bool client_registry_take_tap(uint32_t client_id, uint32_t *kind_out,
+                              uint32_t *age_ms_out) {
+  for (size_t i = 0; i < CLIENT_REGISTRY_MAX; i++) {
+    if (!s_clients[i].active || s_clients[i].info.id != client_id) {
+      continue;
+    }
+    client_info_t *info = &s_clients[i].info;
+    client_registry_expire_tap(info);
+    if (!info->tap_valid) {
+      return false;
+    }
+    if (kind_out != NULL) {
+      *kind_out = info->tap_kind;
+    }
+    if (age_ms_out != NULL) {
+      *age_ms_out = client_registry_ms_since(info->tap_updated_at);
+    }
+    client_registry_clear_tap(info);
+    return true;
+  }
+  return false;
+}
+
 void client_registry_set_master_battery(const board_lipo_reading_t *reading) {
   if (reading == NULL) {
     return;