feat: display app version in UI footer

- Add version package with build-time variables
- Inject version via ldflags in Dockerfile using git describe
- Show version in footer on every page
- Log version and commit on server startup

main.go

@@ -20,6 +20,7 @@ import (
 	"github.com/ryanhamamura/games/router"
 	"github.com/ryanhamamura/games/sessions"
 	"github.com/ryanhamamura/games/snake"
+	"github.com/ryanhamamura/games/version"
 
 	"github.com/go-chi/chi/v5"
 	"github.com/go-chi/chi/v5/middleware"
@@ -45,7 +46,7 @@ func main() {
 func run(ctx context.Context) error {
 	cfg := config.Global
 	addr := fmt.Sprintf("%s:%s", cfg.Host, cfg.Port)
-	slog.Info("server starting", "addr", addr)
+	slog.Info("server starting", "addr", addr, "version", version.Version, "commit", version.Commit)
 	defer slog.Info("server shutdown complete")
 
 	eg, egctx := errgroup.WithContext(ctx)