WIP: Add multiplayer Snake game

N-player (2-8) real-time Snake game alongside Connect 4.
Lobby has tabs to switch between games. Players join via
invite link with 10-second countdown. Game loop runs at
tick-based intervals with NATS pub/sub for state sync.

Keyboard input not yet working (Datastar keydown binding
issue still under investigation).

ui/lobby.go

@@ -1,20 +1,63 @@
 package ui
 
 import (
+	"github.com/ryanhamamura/c4/snake"
 	"github.com/ryanhamamura/via/h"
 )
 
-func LobbyView(nicknameBind, createGameKeyDown, createGameClick h.H, isLoggedIn bool, username string, logoutClick h.H, userGames []GameListItem, deleteGameClick func(id string) h.H) h.H {
+type LobbyProps struct {
+	NicknameBind       h.H
+	CreateGameKeyDown  h.H
+	CreateGameClick    h.H
+	IsLoggedIn         bool
+	Username           string
+	LogoutClick        h.H
+	UserGames          []GameListItem
+	DeleteGameClick    func(id string) h.H
+	ActiveTab          string
+	TabClickConnect4   h.H
+	TabClickSnake      h.H
+	SnakeNicknameBind  h.H
+	SnakePresetClicks  []h.H
+	ActiveSnakeGames   []*snake.SnakeGame
+}
+
+func LobbyView(p LobbyProps) h.H {
 	var authSection h.H
-	if isLoggedIn {
-		authSection = AuthHeader(username, logoutClick)
+	if p.IsLoggedIn {
+		authSection = AuthHeader(p.Username, p.LogoutClick)
 	} else {
 		authSection = GuestBanner()
 	}
 
-	return h.Main(h.Class("max-w-sm mx-auto mt-8 text-center"),
+	connect4Class := "tab"
+	snakeClass := "tab"
+	if p.ActiveTab == "snake" {
+		snakeClass += " tab-active"
+	} else {
+		connect4Class += " tab-active"
+	}
+
+	var tabContent h.H
+	if p.ActiveTab == "snake" {
+		tabContent = SnakeLobbyTab(p.SnakeNicknameBind, p.SnakePresetClicks, p.ActiveSnakeGames)
+	} else {
+		tabContent = connect4LobbyContent(p)
+	}
+
+	return h.Main(h.Class("max-w-md mx-auto mt-8 text-center"),
 		authSection,
-		h.H1(h.Class("text-3xl font-bold"), h.Text("Connect 4")),
+		h.H1(h.Class("text-3xl font-bold mb-4"), h.Text("Game Lobby")),
+		h.Div(h.Class("tabs tabs-box mb-6 justify-center"),
+			h.Button(h.Class(connect4Class), h.Type("button"), h.Text("Connect 4"), p.TabClickConnect4),
+			h.Button(h.Class(snakeClass), h.Type("button"), h.Text("Snake"), p.TabClickSnake),
+		),
+		tabContent,
+	)
+}
+
+func connect4LobbyContent(p LobbyProps) h.H {
+	return h.Div(
 		h.P(h.Class("mb-4"), h.Text("Challenge a friend to a game of Connect 4!")),
 		h.Form(
 			h.FieldSet(h.Class("fieldset"),
@@ -24,19 +67,19 @@ func LobbyView(nicknameBind, createGameKeyDown, createGameClick h.H, isLoggedIn
 					h.ID("nickname"),
 					h.Type("text"),
 					h.Placeholder("Enter your nickname"),
-					nicknameBind,
+					p.NicknameBind,
 					h.Attr("required"),
-					createGameKeyDown,
+					p.CreateGameKeyDown,
 				),
 			),
 			h.Button(
 				h.Class("btn btn-primary w-full"),
 				h.Type("button"),
 				h.Text("Create Game"),
-				createGameClick,
+				p.CreateGameClick,
 			),
 		),
-		GameList(userGames, deleteGameClick),
+		GameList(p.UserGames, p.DeleteGameClick),
 	)
 }