feat: add hashfs for static asset cache busting and live clock

- Add assets package with dev/prod build tags
- Dev: serve from filesystem with Cache-Control: no-store
- Prod: use hashfs for cache-busting URLs
- Add LiveClock component to show SSE connection status
- Update templates to use StaticPath for asset URLs

main.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"context"
-	"embed"
 	"fmt"
 	"log/slog"
 	"net"
@@ -29,9 +28,6 @@ import (
 	"github.com/ryanhamamura/games/version"
 )
 
-//go:embed assets
-var assets embed.FS
-
 func main() {
 	ctx, cancel := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
 	defer cancel()
@@ -97,7 +93,7 @@ func run(ctx context.Context) error {
 		sessionManager.LoadAndSave,
 	)
 
-	router.SetupRoutes(r, queries, sessionManager, nc, store, snakeStore, assets)
+	router.SetupRoutes(r, queries, sessionManager, nc, store, snakeStore)
 
 	// HTTP server
 	srv := &http.Server{