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

router/router.go

@@ -2,8 +2,6 @@
 package router
 
 import (
-	"embed"
-	"io/fs"
 	"net/http"
 	"sync"
 
@@ -12,6 +10,7 @@ import (
 	"github.com/nats-io/nats.go"
 	"github.com/starfederation/datastar-go/datastar"
 
+	"github.com/ryanhamamura/games/assets"
 	"github.com/ryanhamamura/games/config"
 	"github.com/ryanhamamura/games/connect4"
 	"github.com/ryanhamamura/games/db/repository"
@@ -31,11 +30,9 @@ func SetupRoutes(
 	nc *nats.Conn,
 	store *connect4.Store,
 	snakeStore *snake.SnakeStore,
-	assets embed.FS,
 ) {
 	// Static assets
-	subFS, _ := fs.Sub(assets, "assets")
-	router.Handle("/assets/*", http.StripPrefix("/assets/", http.FileServerFS(subFS)))
+	router.Handle("/assets/*", assets.Handler())
 
 	// Hot-reload for development
 	if config.Global.Environment == config.Dev {