chore: gitignore generated _templ.go files, track .templ sources

Generated _templ.go files are deterministic output from .templ sources,
same as output.css from input.css. Remove them from version control to
reduce diff noise and merge conflicts. Add build:templ and live:templ
tasks to the Taskfile so generation happens as part of the build.

features/snakegame/pages/game.templ

@@ -0,0 +1,75 @@
+package pages
+
+import (
+	"fmt"
+
+	"github.com/ryanhamamura/c4/features/common/components"
+	"github.com/ryanhamamura/c4/features/common/layouts"
+	snakecomponents "github.com/ryanhamamura/c4/features/snakegame/components"
+	"github.com/ryanhamamura/c4/snake"
+	"github.com/starfederation/datastar-go/datastar"
+)
+
+// keydownScript builds the inline JS for a single data-on:keydown handler
+// that dispatches WASD/arrow keys to direction POST endpoints.
+func keydownScript(gameID string) string {
+	return fmt.Sprintf(
+		"const k=evt.key;"+
+			"if(k==='w'||k==='ArrowUp'){evt.preventDefault();%s}"+
+			"else if(k==='s'||k==='ArrowDown'){evt.preventDefault();%s}"+
+			"else if(k==='a'||k==='ArrowLeft'){evt.preventDefault();%s}"+
+			"else if(k==='d'||k==='ArrowRight'){evt.preventDefault();%s}",
+		datastar.PostSSE("/snake/%s/dir?d=0", gameID),
+		datastar.PostSSE("/snake/%s/dir?d=1", gameID),
+		datastar.PostSSE("/snake/%s/dir?d=2", gameID),
+		datastar.PostSSE("/snake/%s/dir?d=3", gameID),
+	)
+}
+
+templ GamePage(sg *snake.SnakeGame, mySlot int, messages []snakecomponents.ChatMessage, gameID string) {
+	@layouts.Base("Snake") {
+		<main
+			class="snake-wrapper flex flex-col items-center gap-4 p-4"
+			data-signals={ `{"chatMsg":""}` }
+			data-init={ datastar.GetSSE("/snake/%s/events", gameID) }
+			data-on:keydown.throttle_100ms={ keydownScript(gameID) }
+			tabindex="0"
+		>
+			@components.BackToLobby()
+			<h1 class="text-3xl font-bold">~~~~</h1>
+			@snakecomponents.PlayerList(sg, mySlot)
+			@snakecomponents.StatusBanner(sg, mySlot, gameID)
+			if sg.Status == snake.StatusInProgress || sg.Status == snake.StatusFinished {
+				if sg.Mode == snake.ModeMultiplayer {
+					<div class="snake-game-area">
+						@snakecomponents.Board(sg)
+						@snakecomponents.Chat(messages, gameID)
+					</div>
+				} else {
+					@snakecomponents.Board(sg)
+				}
+			} else if sg.Mode == snake.ModeMultiplayer {
+				@snakecomponents.Chat(messages, gameID)
+			}
+			if sg.Mode == snake.ModeMultiplayer && (sg.Status == snake.StatusWaitingForPlayers || sg.Status == snake.StatusCountdown) {
+				@snakecomponents.InviteLink(gameID)
+			}
+		</main>
+	}
+}
+
+templ JoinPage(gameID string) {
+	@layouts.Base("Snake - Join") {
+		@components.GameJoinPrompt(
+			fmt.Sprintf("/login?return_url=/snake/%s", gameID),
+			fmt.Sprintf("/register?return_url=/snake/%s", gameID),
+			fmt.Sprintf("/snake/%s", gameID),
+		)
+	}
+}
+
+templ NicknamePage(gameID string) {
+	@layouts.Base("Snake - Join") {
+		@components.NicknamePrompt(fmt.Sprintf("/snake/%s/join", gameID))
+	}
+}