Add guest tally (on air / off air) and host connection warning

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

main.go

@@ -89,6 +89,7 @@ type Hub struct {
 	call      *Call
 	hosts     map[*wsConn]bool
 	chat      []chatMsg
+	onAir     bool // tally shown on the guest page; set by the host, never automatic
 	udp       *net.UDPConn
 	mux       ice.UDPMux
 }
@@ -129,6 +130,7 @@ func (h *Hub) stateLocked() map[string]any {
 		"link":        h.link(),
 		"guestOnline": h.guest != nil,
 		"guestName":   h.guestName,
+		"onAir":       h.onAir,
 		"call":        nil,
 	}
 	if h.call != nil {
@@ -322,13 +324,14 @@ func guestWS(w http.ResponseWriter, r *http.Request) {
 	old := hub.guest
 	hub.guest = me
 	hist := append([]chatMsg(nil), hub.chat...)
+	onAir := hub.onAir
 	hub.mu.Unlock()
 	if old != nil {
 		old.send(map[string]any{"t": "ended", "reason": "This link was opened in another window."})
 		old.c.Close()
 	}
 	log.Printf("guest connected from %s", r.Header.Get("X-Real-IP"))
-	me.send(map[string]any{"t": "welcome", "hostLabel": *hostLabel, "history": hist})
+	me.send(map[string]any{"t": "welcome", "hostLabel": *hostLabel, "history": hist, "onAir": onAir})
 	hub.pushState()
 
 	chatRL := &rateLimiter{n: 8, per: 10 * time.Second}
@@ -447,6 +450,7 @@ func hostWS(w http.ResponseWriter, r *http.Request) {
 		var m struct {
 			T    string `json:"t"`
 			Text string `json:"text"`
+			On   bool   `json:"on"`
 		}
 		if err := c.ReadJSON(&m); err != nil {
 			return
@@ -462,6 +466,7 @@ func hostWS(w http.ResponseWriter, r *http.Request) {
 			hub.token = randToken()
 			hub.chat = nil
 			hub.guestName = ""
+			hub.onAir = false
 			hub.saveToken()
 			hub.mu.Unlock()
 			log.Printf("new invite link created")
@@ -471,6 +476,7 @@ func hostWS(w http.ResponseWriter, r *http.Request) {
 			hub.kickGuest("The host closed this session.")
 			hub.mu.Lock()
 			hub.token = ""
+			hub.onAir = false
 			hub.saveToken()
 			hub.mu.Unlock()
 			log.Printf("invite link revoked")
@@ -485,6 +491,16 @@ func hostWS(w http.ResponseWriter, r *http.Request) {
 			if g != nil {
 				g.send(map[string]any{"t": "callended"})
 			}
+		case "onair":
+			hub.mu.Lock()
+			hub.onAir = m.On
+			g := hub.guest
+			hub.mu.Unlock()
+			log.Printf("tally: on air %v", m.On)
+			if g != nil {
+				g.send(map[string]any{"t": "onair", "on": m.On})
+			}
+			hub.pushState()
 		case "clearchat":
 			hub.mu.Lock()
 			hub.chat = nil