feat: re-enable connection indicator for SSE status

Add ConnectionIndicator to Connect 4 game page (Snake already had it).
Both games now patch the indicator on initial connect and every 10s
heartbeat, giving users visual feedback that SSE is connected.

features/c4game/pages/game.templ

@@ -18,6 +18,7 @@ templ GamePage(g *connect4.Game, myColor int, messages []chat.Message, chatCfg c
 			data-signals="{chatMsg: ''}"
 			data-init={ fmt.Sprintf("@get('/games/%s/events',{requestCancellation:'disabled'})", g.ID) }
 		>
+			@sharedcomponents.ConnectionIndicator(0)
 			@GameContent(g, myColor, messages, chatCfg)
 		</main>
 	}