feat: replace connection indicator with live clock

A ticking clock serves as an implicit connection indicator - if it
stops updating, users know the connection is stale. Simpler and more
useful than a status dot.

features/c4game/pages/game.templ

@@ -25,6 +25,7 @@ templ GamePage(g *connect4.Game, myColor int, messages []chat.Message, chatCfg c
 
 templ GameContent(g *connect4.Game, myColor int, messages []chat.Message, chatCfg chatcomponents.Config) {
 	<div id="game-content">
+		@sharedcomponents.LiveClock()
 		@sharedcomponents.BackToLobby()
 		@sharedcomponents.StealthTitle("text-3xl font-bold")
 		@components.PlayerInfo(g, myColor)