refactor: patch connection indicator with timestamp

Server patches the ConnectionIndicator element with a timestamp on
each heartbeat. Client-side JS checks every second if the timestamp
is stale (>20s) and toggles red/green accordingly.

This properly detects connection loss since the indicator will turn
red if no patches are received.

features/snakegame/handlers.go

@@ -13,6 +13,7 @@ import (
 
 	"github.com/ryanhamamura/games/chat"
 	chatcomponents "github.com/ryanhamamura/games/chat/components"
+	sharedcomponents "github.com/ryanhamamura/games/features/common/components"
 	"github.com/ryanhamamura/games/features/snakegame/pages"
 	"github.com/ryanhamamura/games/sessions"
 	"github.com/ryanhamamura/games/snake"
@@ -125,7 +126,7 @@ func HandleSnakeEvents(snakeStore *snake.SnakeStore, nc *nats.Conn, sm *scs.Sess
 		}
 
 		sendPing := func() error {
-			return sse.PatchSignals([]byte(fmt.Sprintf(`{"lastPing":%d}`, time.Now().UnixMilli())))
+			return sse.PatchElementTempl(sharedcomponents.ConnectionIndicator(time.Now().UnixMilli()))
 		}
 
 		// Send initial render and ping