refactor: rename game package to connect4, drop Game prefix from types

Rename game/ -> connect4/ to avoid c4/game stutter. Drop redundant
Game prefix from exported types (GameStore -> Store, GameInstance ->
Instance, GameStatus -> Status). Rename NATS subjects from game.{id}
to connect4.{id}. URL routes unchanged.

features/c4game/pages/game.templ

@@ -3,14 +3,14 @@ package pages
 import (
 	"github.com/ryanhamamura/c4/chat"
 	chatcomponents "github.com/ryanhamamura/c4/chat/components"
+	"github.com/ryanhamamura/c4/connect4"
 	"github.com/ryanhamamura/c4/features/c4game/components"
 	sharedcomponents "github.com/ryanhamamura/c4/features/common/components"
 	"github.com/ryanhamamura/c4/features/common/layouts"
-	"github.com/ryanhamamura/c4/game"
 	"github.com/starfederation/datastar-go/datastar"
 )
 
-templ GamePage(g *game.Game, myColor int, messages []chat.Message, chatCfg chatcomponents.Config) {
+templ GamePage(g *connect4.Game, myColor int, messages []chat.Message, chatCfg chatcomponents.Config) {
 	@layouts.Base("Connect 4") {
 		<main
 			class="flex flex-col items-center gap-4 p-4"
@@ -25,7 +25,7 @@ templ GamePage(g *game.Game, myColor int, messages []chat.Message, chatCfg chatc
 				@components.Board(g, myColor)
 				@chatcomponents.Chat(messages, chatCfg)
 			</div>
-			if g.Status == game.StatusWaitingForPlayer {
+			if g.Status == connect4.StatusWaitingForPlayer {
 				@components.InviteLink(g.ID)
 			}
 		</main>