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>

goTool/tap_notify_ctl.go

@@ -0,0 +1,50 @@
+package main
+
+import "sync"
+
+// tapNotifyCtl tracks which slaves have tap notify enabled (mirrors firmware / dashboard).
+type tapNotifyCtl struct {
+	mu    sync.Mutex
+	flags map[uint32]tapNotifyFlags
+}
+
+type tapNotifyFlags struct {
+	single    bool
+	doubleTap bool
+	triple    bool
+}
+
+func newTapNotifyCtl() *tapNotifyCtl {
+	return &tapNotifyCtl{flags: make(map[uint32]tapNotifyFlags)}
+}
+
+func (c *tapNotifyCtl) Set(clientID uint32, single, doubleTap, triple bool) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if !single && !doubleTap && !triple {
+		delete(c.flags, clientID)
+		return
+	}
+	c.flags[clientID] = tapNotifyFlags{single: single, doubleTap: doubleTap, triple: triple}
+}
+
+func (c *tapNotifyCtl) Any() bool {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return len(c.flags) > 0
+}
+
+func (c *tapNotifyCtl) SyncFromClients(clients []ClientView) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.flags = make(map[uint32]tapNotifyFlags)
+	for _, cl := range clients {
+		if cl.TapNotifySingle || cl.TapNotifyDouble || cl.TapNotifyTriple {
+			c.flags[cl.ID] = tapNotifyFlags{
+				single:    cl.TapNotifySingle,
+				doubleTap: cl.TapNotifyDouble,
+				triple:    cl.TapNotifyTriple,
+			}
+		}
+	}
+}