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/proto/uart_messages.proto

@@ -25,6 +25,8 @@ enum MessageType {
   ACCEL_SNAPSHOT = 24;
   ACCEL_STREAM = 25;
   BATTERY_STATUS = 26;
+  TAP_NOTIFY = 27;
+  TAP_SNAPSHOT = 28;
 }
 
 message UartMessage {
@@ -57,6 +59,10 @@ message UartMessage {
     AccelStreamResponse accel_stream_response = 26;
     BatteryStatusRequest battery_status_request = 27;
     BatteryStatusResponse battery_status_response = 28;
+    TapNotifyRequest tap_notify_request = 29;
+    TapNotifyResponse tap_notify_response = 30;
+    TapSnapshotRequest tap_snapshot_request = 31;
+    TapSnapshotResponse tap_snapshot_response = 32;
   }
 }
 
@@ -83,6 +89,10 @@ message ClientInfo {
   uint32 version = 7;
   /** Master: ESP-NOW accel stream enabled for this slave. */
   bool accel_stream_enabled = 8;
+  /** Master: ESP-NOW tap notify flags for this slave. */
+  bool tap_notify_single = 9;
+  bool tap_notify_double = 10;
+  bool tap_notify_triple = 11;
 }
 
 message ClientInfoResponse { 
@@ -180,6 +190,48 @@ message AccelSnapshotResponse {
   repeated AccelSample samples = 1 [(nanopb).max_count = 16];
 }
 
+/** Host → master: enable/disable tap ESP-NOW notify per slave (single/double/triple). */
+message TapNotifyRequest {
+  bool write = 1;
+  uint32 client_id = 2;
+  bool all_clients = 3;
+  bool single = 4;
+  bool double_tap = 5;
+  bool triple = 6;
+}
+
+message TapNotifyResponse {
+  uint32 client_id = 1;
+  bool success = 2;
+  uint32 slaves_updated = 3;
+  bool single = 4;
+  bool double_tap = 5;
+  bool triple = 6;
+}
+
+enum TapKind {
+  TAP_NONE = 0;
+  TAP_SINGLE = 1;
+  TAP_DOUBLE = 2;
+  TAP_TRIPLE = 3;
+}
+
+/** Host → master: read cached tap events (discarded after reply or when age > 16 ms). */
+message TapSnapshotRequest {
+  uint32 client_id = 1;
+}
+
+message TapEvent {
+  uint32 client_id = 1;
+  bool valid = 2;
+  TapKind kind = 3;
+  uint32 age_ms = 4;
+}
+
+message TapSnapshotResponse {
+  repeated TapEvent events = 1 [(nanopb).max_count = 16];
+}
+
 message EspNowUnicastTestRequest {
   uint32 client_id = 1;
   uint32 seq = 2;